If anything, new frameworks should be simple to use.
I've had the misfortune to work in an Angular codebase last year, I could hardly make heads or tails from it; I'm sure there's good theory behind it, but it was far too complicated.
Currently working in React, and it's got the annoyances of hooks, callbacks, effects, etc; basically, you as a developer are responsible for a lot of rendering behaviour, using what looks like magic trickery. Don't get me wrong, I like the basics of React, but as soon as it goes beyond simple props it's starting to lose me. I heard Vue solved this better or more intuitively, but it's still a layer on top of JS/HTML.
In parallel I've been working in Go, and while it's wordy and frequently annoying (like when using the correct design patterns, you'll end up copying a database struct to a business logic struct to a HTTP API struct, it's boring, wordy and bug prone code), it's still much more of a joy to work in because there's very little indirection or friction.
A while ago, a few years I think, I learned react with class components. Hooks were never mentioned, so I don't know if they didn't exist yet or were in some nascent stage. I thought "huh neat this makes writing js not completely awful" - my only "frontend"-related background was in desktop UI development with Swing and Qt and such. As I mentioned, I'm mostly a backend dev.
Anyway, I wrote a small internal app for my job at the time and shipped it and it was neat, all the other backend devs (we had ~no frontend devs) were suitably impressed with how much less awful react was than vanilla JS.
Fast forward... I suspect 3-ish years. Suddenly hooks were popular and class components were not and people were being pushed to migrate (since newer versions of libraries were preferring hooks). My hard-won frontend knowledge is already outdated! And imagine my surprise when I learned SSR was back?? and something about next.js which I guess is still react but it's a server packaging of it as well and that bleeds over into letting you do more stuff on the frontend, something about server-side props? I was disappointed with how much had changed despite the actual product - the websites you can build - still essentially staying the same.
And this is just for React - the winner! I had managed to correctly pick the winner and there's still all this churn. Meanwhile, as you mentioned, rails is still almost exactly the same (all its churn has been trying to pick a not-awful way to integrate javascript, ironically) despite several major versions passing, Spring is the same, etc.
All I want to add is that today React is the winner, last week, backbone/ember was, week before that it was angular.
Even winners are transient and ephemeral.
That being said, I do love Astro. It's a very nice, easy experience.
All this is to say that there are projects and communities that value stability with stagnating so you can still have “nice things” without feeling stuck on a hamster wheel.
I watched everyone adopt AngularJS and then have to migrated to Angular 2.0 and then everyone migrated to React. During this time, the backend folks wrote java services using SpringBoot and then migrated to SpringBoot and then when that wasn't abandoned, moved to SpringBoot.
Web development feels way too much like a hamster wheel to me.