ABSOLUTELY NOT!
Warning, this post may contain harsh language levied against WYSIWYG's, frameworks, and their creators. If that's going to get your panties in a wad do me and everyone else a favor, and just stop reading NOW!
Let's call these what they are: WYSIWYG's that use frameworks, and that's a double-whammy of developer incompetence and ineptitude! They are a trap for nubes and rubes to THINK they can build a website, but all you end up producing is an inaccessible inefficient train wreck laundry list of how NOT to build a website!
That's not being a 'luddite' or a stick-in-the-mud or feeling threatened by them. It's the response to the broken, borked, inaccessible disasters that tell large swaths of potential users to go plow themselves; much less the pain, agony, and overhead such bloated trash HTML ends up burdening the back-end developers with trying to incorporate.
We already fought and 'mostly' won this battle once. There's a reason chazerei like Frontpage and Dreamweaver has gone the way of the dodo amongst QUALIFIED developers, and the few newer programs that try to fill their shoes are just as flawed.
Simply put, WYSIWYG's / visual design CANNOT maintain a proper separation of presentation from content and they certainly DO NOT produce semantic markup. This flips the bird at all non screen-media users including those using screen readers (software that reads the page aloud), braille readers, and of course search engines.
Since as the joke goes, search engines don't have eyeballs and they sure as shine-ola don't care about your layout.
Such "Visual design" tools have not one blasted thing to do with ACTUAL design, since they are by their very nature about visuals and layout, and not the underlying specifications, requirements, or accessibility norms that separate art from design.
They are a crutch for those who cry "wah wah, I don't wanna learn" and the sites that result ALWAYS do more harm than good.
... and that's just the concept of the editor. THEN you have that they rely on dumbass framework TRASH like bootcrap. Where separation of presentation from content and logical semantics is pissed on from so on-high you'd think the almighty just got back from a kegger!
As I'm always saying about HTML/CSS frameworks is that those CREATING them have so spectacularly failed to divine the purpose of HTML, what 4 Strict was trying to drag us towards, and why CSS is a separate specification that it becomes clear not ONE of the lot is qualified to write a single line of HTML.
You can go into ANY bootstrap codebase and they are littered with presentational use of classes with little to no semantics. If you don't know what's wrong with classes like "box-shadow", "text-center", or "col-md-4" you might as well go back to 1997 and writing pre-CSS HTML 3.2 style markup.
ADMITTEDLY that's what most people are STILL doing and how they think about building their pages. Zero concern for accessibility, the specifications, or anything else. It's why the majority of developers spent a decade and a half writing HTML 3.2 and slapped the 4 tranny doctype atop it, failing to embrace the entire concept of HTML itself (which 3.2 and the browser proprietary crap adopted by Tranny missed by a mile and a half) much less the advantages of CSS. Today they just wrap the 5 lip-service doctype around the same outdated and outmoded techniques so they can congratulate themselves over how 'modern' they are.
Even the examples on bootstrap's own website are RIDDLED with -- not to overuse the words -- ignorance and incompetence. It is painfully clear that even those making their example pages do not know enough HTML to be writing a single blasted line of it!
See such mentally enfeebled gems as:
<body>
<header>
<div class="collapse bg-dark" id="navbarHeader">
<div class="container">
<div class="row">
<div class="col-sm-8 col-md-7 py-4">
<h4 class="text-white">About</h4>
<p class="text-muted">Add some information about the album below, the author, or any other background context. Make it a few sentences long so folks can pick up some informative tidbits. Then, link them off to some social networking sites or contact information.</p>
</div>
<div class="col-sm-4 offset-md-1 py-4">
<h4 class="text-white">Contact</h4>
<ul class="list-unstyled">
<li><a href="#" class="text-white">Follow on Twitter</a></li>
<li><a href="#" class="text-white">Like on Facebook</a></li>
<li><a href="#" class="text-white">Email me</a></li>
</ul>
</div>
</div>
</div>
</div>
<div class="navbar navbar-dark bg-dark box-shadow">
<div class="container d-flex justify-content-between">
<a href="#" class="navbar-brand d-flex align-items-center">
<svg xmlns="w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="mr-2"><path d="M23 19a2 2 0 0 1-2 2H3a2 2 0 0 1-2-2V8a2 2 0 0 1 2-2h4l2-3h6l2 3h4a2 2 0 0 1 2 2z"></path><circle cx="12" cy="13" r="4"></circle></svg>
<strong>Album</strong>
</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarHeader" aria-controls="navbarHeader" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
</div>
</div>
</header>
For proof enough of that.
... and it's not even the HTML / CSS alone in the "hurr durrz eyes cans haz teh intarwebs" coding -- this is further exacerbated by the use of JavaScript for things CSS can do all on its lonesome in less code!
Hence why it's not unusual -- in fact it's the norm -- for sites slopped together with front-end frameworks to write as much of their own CSS as they'd have without the frameworks to do anything unique, and two to ten times the markup needed for the bloody job!
But again, tell me how writing ten times the HTML is 'easier', 'simpler', 'more efficeint', or 'makes you more productive'.
Laugh being bootcrap is one of the BETTER ones. Have you seen the monument to stupidity from the dirtbag scam artists over at W3Schools? "w3.css" is without a doubt the biggest mountain of garbage with its fans perched atop it screaming "We miss ALIGN, BORDER, CENTER, FONT, and tables for layout!" like blind parrots.
So... combining WYSIWYG ignorance with HTML/CSS framework incompetence? /FAIL/ HARD
No qualified front end developer should even be looking at those underlying frameworks, much less some garbage WYSIWYG for dealing with them. The only thing you can learn from either is how NOT to build a website -- no matter how many fanboys mindlessly parrot their praises thanks to propaganda and echo-chamber indoctrination.
In fact, any QUALIFIED developer can simply go view-source on the websites for these projects and/or any provided examples, and if you don't recoil in HORROR at what they have the unmitigated gall to call HTML, you're not as qualified as you think!
I have NEVER seen any of that GARBAGE produce a website that was worth a flying purple fish... and before anyone out there goes "wah wah, he's attacking us" how about providing an example of a site that disproves anything I'm saying.
Betcha can't, which is why the typical response is nothing more than a crybaby "Is not" and kvetching about how I "DARED" use a little harsh language to describe something that deserves a far, FAR harsher treatment than I can give it here.
I'm all for more tools in the toolbag, but I'm not going to try to use a banana to drive a nail.