But bicycles don't stop existing because they become cars. In computing there is this bad habit of over-designing everything, so that in the end you don't have any simple things left.
You aren’t wrong, and frankly I am dismayed at the new API in Vue 3. It does feel like a downgrade in structure for a dubious gain.
But framework and complex are not synonymous. I like well designed frameworks that let me get shit done without getting in the way. Vue is pretty close to that. Django is very close to that. If I could have Vue 2.x supporter permanently I would be happy. It lacked native forms support but router and VueX made it nearly perfect.
In practice they absolutely are. The average project using a popular batteries-included framework uses a fraction of it's functionality. Composing smaller libraries will always result in less lines of code running in production. Usually by an order of magnitude.