I think it's more nuanced than that. The original React model of UI = f(state) is pretty simple and solved the state management issue. Building your UI with function composition isn't a massive jump in complexity
..but then they kept adding. And adding. And adding. And adding.. and now where are we? Death by a thousand cuts. 10x the complexity for an additional 7% benefit
React is pretty barebones, they keep adding stuff because how ugly the original one looks like and how outdated feels like compared to "modern" ones like Vue, Svelte, etc...
You don’t have to use all that other stuff. React works best if you prioritize function composition. So much of the ecosystem is there to support the people that don’t know what composition is.