We know you meant "composition api" but while I agree there are some good improvements sprinkled in Vue 3, I deeply lament now that we have literally two core competing APIs -- the classic "options" api, and the newer "composition" api.
Now when starting a new project there has to be a debate. Some people will advocate for trying the new thing, and as many others will be more conservative.
Worse, within a project there is now opportunity for competing technical approaches allover everywhere.