Yeah it is an interesting one. There is definitely a slowdown due to the amount of wrapping that happens. These sort of libraries tend to put component in component in component etc.. so there is a lot of prop iteration, Object.keys calls in Object.keys calls etc which when used with proxies can add up a bit. The tricky part is no one actually knows how slow these libraries are in say React. My suspicion they are slow there as well but maybe not as stark of a difference because of how fast Solid to begin with comparatively.

People who use Solid tend to measure stuff like this where as those who use React might have already reconciled themselves to performance issues.