Comment by kypro
React's dominance is genuinely baffling to me, and even more so popularity of Next.js.
In my experience React is rarely the best solution and adds a huge amount of complexity which is often completely unnecessary because React is rarely needed.
In the early days my very controversial view was that frontend developers tend to be fairly mediocre developers, and this is why a lot of frontend frameworks suck and frontend developers just mindlessly adopt whatever the hot new technology is with seemingly no concern for performance, maintainability, security, etc.
But honestly I'm not sure this explains it anymore... There are a lot of really talented frontend development teams out there working for companies with plenty of cash to try something different. I don't really understand why there's no serious competitor frameworks in terms of market share out there.
As far as I'm aware there's no analogies to this in other areas of the web tech stack. There's plenty of backend frameworks to pick from depending on the product. There's also plenty of competitive DBMSs, cloud providers, package managers, code editors, etc, etc. I don't understand why frontend development is so static in comparison because it's certainly not that React is the perfect solution for everything.
For sure it isn't the perfect solution for everything, and I say that as someone who spends most of their time in either React or Angular now. For application-like development or just sites with tons of interaction it's become as standard as reaching for Spring or PSQL though.
I can't speak to the complexity you've encountered, but for me it's pretty much zero. A button component is just a function. React-Router is good enough and code splitting is pretty much just changing how to import something. Component state is dead-easy to write by just adding a useState hook. Bundlers pretty much handle everything these days so not to much concern about size.
Your view on front-end developers having been mediocre in the past isn't far off though, at least in my experience. I noticed a big difference between the people who wanted to build nice looking pages and the ones that wanted to build applications myself. Even today it amazes me how many people have never unit tested their code, have no idea about layering an application and have poor JS/TS fundamentals. It's gotten a lot better though.
Ultimately it isn't perfect for everything, but for a lot of people it's an easy choice. And for me personally, the tons of other JS frameworks do very little in that area that I'd pick them. I'd rather spend my time working on the product. Lol, maybe its just the default because its the default at this point.