As a former user who had one of those typical personal Wordpress blogs on a shared hosting setup, I experienced the nightmare of dealing with spam, hacking, having to constantly upgrade, etc. So for my own use I would never consider anything other than a static site generator; but I can see the appeal for many use cases, especially if the backend is managed (services like WP Engine) or semi-managed (the guy who set it up is getting a small monthly fee to keep an eye on things).
My sense is that WP Engine targets busy professionals who have first-hand experience of how much hassle a WP installation can be to maintain, people for whom downtime or being hacked has potentially a severe cost in terms of lost business, reputational damage, etc. The other way to look at it is that $300/mo sounds like a lot for "just a WP installation", but it's peanuts compared to hiring another person for your IT department.
You're also paying for decent support tech's and support availability. I think to this day you can call and a human will pick up the phone. Tech's are well versed in the WordPress ecosystem and many are developers who can help you troubleshoot things at the code level, whereas with some budget webhost, they'll tell you to pound sand and hang up (albeit more politely).
That said, I think these "premium" WordPress hosts are purely for non-devs or devs with no time to provide their own support. If you're a developer, there is no reason to pay that premium to keep your blog online. If you want a more managed solution, use something like ServerPilot or SpinUp WP, or any number of other service that will provide a thin maintenance layer on top of any garden variety VPS provider.
Very simple and more then did the job. It costed basically nothing to use and pretty much anyone could maintain the site.
The API will have an official plugin, or someone will have written one because their client needed it and the dev decided to support and sell it. Complicated forms can be turned out with plugins like Gravity forms.
This is why lots and lots of sites are still built on wordpress because the ecosystem around it lets people do a lot of stuff quickly without touching a line of code.