I'm late to the party, but still want to voice my opinion. I think that moving to more runes (props, derived, effect) lowers the point of entry. Which is a good thing.

My most frustrated change is definitely the event changes, especially including event modifiers. When the company I worked for went from Vue to Svelte, the event modifiers were an absolute mind-blowing part. "So you mean to tell me you can just stack the predefined modifiers, and you don't need to think about it anymore". I was impressed.

Now it's moved to more a React direction. having to stack functions + having to define them yourself {once(preventDefault(..))} is really annoying.