I am not only a developer, so the answer is it depends.
I personally don't use managed systems, I do it myself or I pay a really good admin to build it for me. But than that's how I approach things, there are different perspectives and values at play.
For normal developers they usually suck at system administration and there knowledge of an OS ends with the copy paste tutorial and their 4 projects where they wanted to do XYZ and need some insights.
So they should definitely use managed systems with automated redundancies integrated and so on.
To me they are usually little value for the small scale, because I need to practice my admin skills anyways so yeah .... values I get value out of it not using AWS others want AWS ....
There are even certain scenarios where it makes sense to have those externalities but we're talking big league here, for the others it's just being lazy most of the time.
Anyhow that's how I see it.