>React only skips over stuff that's provably unchanged. But in many - most? web apps, it rerenders a lot. Yeah, you can add memoization hints. But how many people actually do that?

Even without any hints, it doesn't re-render "the entire view tree" like your parent comment claims, but only stuff below the place that's updated. E.g. if you're updating a text box, only stuff under the component owning that text box's state is considered for reconciliation.

Re: manual memoization hints, I'm not sure what you mean — `useMemo` and `useCallback` are used all over the place in React projects, often unnecessarily. It's definitely something that people do a lot. But also, React Compiler does this automatically, so assuming it gets wider adoption, in the longer run manual hints aren't necessary anyway.

>Where is the rest of the complexity of react?

It's kind of spread around, I wouldn't say it's one specific piece. There's some complexity in hydration (for reviving HTML), declarative loading states (Suspense), interruptible updates (Transitions), error recovery (Error Boundaries), soon animations (View Transitions), and having all these features work with each other cohesively.

I used to work on React, so I'm familiar with what those other libraries do. I understand the things you enjoy about Solid. My bigger point is just that it's still a very different programming model as VB6 and such.