The difference between observer approaches like SolidJS or MobX (and I'd also put Svelte in this box) and React's data-flow centric one is one of explicitness. With the observer approach change tracking is more implicit, i.e. embedded into the values you are using and the functions that are using it. Which does fix the problem of forgetting to declare dependencies, because using == declaring.
Now what it does not guard you against *per se* is unnecessary re-runs, I am willing to bet there are tricky cases with tracking of nested objects and updates based on partial changes there. SolidJS does expose various tools for untracking and batching signals, so it might be a matter of trading initial explicitness/complexity for adding it later.
This might be the right trade-off and untracking might be the smaller problem. But that feels like a somewhat team and product specific question. I think it is clear that without state libs React is to barebone to handle most somewhat-complex interactive apps, and a lot of them are observer based (MobX, Recoil, ...). But I do not see it as a silver bullet just yet.