The answer tends to be "wellll I hate most of these features anyways, let's get rid of them and then it can be as simple as HackerNews!" But obviously, millions of people use those features every day and like them. The tooling solves a real problem.
Desktop and Mobile application are reasonably robust, have very complex software and could do everything Facebook does trivially. All this 'robust tooling' has evolved because we are trying to shove an application into a browser, and despite decades of effort. it still kinda sucks.
If Apple, Microsoft and various distributions of Linux pulled the finger out of their collective asses and agreed on a half-decent, cross-platform GUI software package in 2005, none of this JS madness would exist.
And cross-platform APIs, cross-platform libc, cross-platform networking... and then the same shuffle on mobile, making sure everything is compatible? Supporting x86 and ARM?
The web does suck, there's no getting around that. HTML and the DOM are garbage even at their original purpose, let alone at writing applications, and everything on top of that is a kludge on a kludge on a kludge.
But let's not pretend dealing with OS APIs from the 90s is much better. We've been trying to get away from that as early as we could with e.g. Java.
I work in Fintech. There's a lot of tooling to make JS-as-a-language more robust, including TypeScript and some of the best linters, debuggers and introspective libraries available in the entire tech industry.
The only reason JS isn't used more than it is, is because its robustness is young, not non-existent.
This is what browsers are. You are describing browsers. They run on any device, on any architecture, and nowadays even on the edge. This isn't just about GUIs. I can't stand this lazy mentality of "pfft, I know better than these billion dollar companies, have they tried just making it good???"