What's stopping you from doing these things? You can still write a php file and upload it to any hoster and it'll work.
Exactly this!
My personal website is pure html and css on a custom backend. I do not find the combination lacking.
Not saying this is the case because I don't know you, but that's been the common theme for a long time.
It's like hearing a carpenter complaining their hammer is just not good and nobody should use hammers and they should instead use a screwdriver because everyone knows how bad and outdated hammers are.
[1]: https://w3techs.com/technologies/history_overview/programmin...