Avoid unnecessary re-hydrations (with Signals?)

[mikkpokk]

We all know, hydration and re-hydration (or re-rendering) costs a lot of CPU and may block main-thread while doing it on large application. The fact, we cannot do anything to eliminate or reduce CPU cost of initial hydration (only React can), I propose Remix should at least minimize re-hydrations when possible.

Currently, every loader revalidation causes full tree re-hydration twice (with strict mode 4 times), even when data has not been changed, due to React's context nature. I described the issue more deeply here. Unfortunately, it were closed without understanding issue report correctly. I don't think unnecessary re-renders should be marked as "expected behaviour". However, I understand this particular context is really hard to inform how it has to be memoized since there are a lot of data and callbacks inside.

But.. The answer might be to use signals instead of React state & context inside Remix and react-router. Nature of the Signals is to avoid unnecessary revalidations on the tree, which results in better performing app.

Of course, switching is not as easy as it sounds, but I think it deserves consideration.