If you're going to call HTML a programming language than when you talk about server-side work you must include XML as a programming language (I see markup far different, more simplistic than a programming language). CSS is simply properties applied to the same markup but I digress; I could see the argument argued either way.
Regardless, you can minimize what you're saying down to just HTML, CSS and a server-side language. You can make good applications without a single line of JavaScript and depending on your purpose you may not need persistent storage in the backend. In fact you can write an entire web application with just HTML, CSS and JS if you want and have no backend (beyond a CDN unless you want to be super pedantic and call that a "backend" but I think that would exceptionally overstate what it does).
> And then come the (leaky) abstractions on top of them:
God, you don't need any of these. JS isn't that bad anymore. It's actually kinda nice in some ways. Same with CSS it's rather easy and there are far lighter projects than bootstrap if you want to do minimal stuff, quickly (but there isn't any reason you can't look at tutorials if you're new and get a CSS layout working pretty quickly sans framework).
For server side this depends on your language. Node has a great built in http capability that many seem to ignore (it's quite easy to write your own web server using it; in fact it doesn't take much more code than plugging into express or hapi). Alternatively other languages have even better, built-in ways of handling server-side logic.
> ...and often...
Ugh, SQL is so easy I don't understand why people even bother with these. Every single time I've been involved in a team that used these abstractions it worked great initially and then steered us off a cliff in the end.
Just don't. RDMS is easy.