What are the caveats? Why doesn't everybody use preact instead of react?
There’s not many. I used it for several years on theoutline.com and it was great
I have built https://gridjs.io on top of Preact. It's pretty stable and the API is very nice. Supports most events/callbacks that React has (nothing against Hyperapp though)
there's a valuable comment if I ever saw one
This.
I like how HyperApp takes this to another level, but the ecosystem of Preact is simply better.