If we're talking about landing pages that don't necessarily need to be strong on the code side since you don't expect people to just google them up, there are a lot of generators out there.
All of these tools generate super bad and unreadable code, possibly even making the page non-SEO friendly. However, if your employer is doing some other things to get people on that page and do some stuff (download the product, ebook...), then it's just fine.
Most of these tools exist so that the marketing departments don't have to sit and wait for the development teams to make minor changes when they can just reposition the elements around the page themselves.
If you're wondering how to make a clean & performant page from ground up, with the goal of helping your colleagues, then maybe ask them if they'd want that. Fixing someone else's code takes more time than just writing it on your own.