I'll share my personal experience, which is that the move to Vue.js 2 was fairly straightforward. The project's handy "migration helper" helped a lot. Still, it's not something I jumped on immediately.

I haven't upgraded my projects to Webpack 2 yet. I'm interested but not compelled to, and I'll do it when it makes sense for me.

Does that make JavaScript a bad ecosystem? I have a hard time thinking of thoughtful major releases as a bad thing.

imo Migrating to either one wasn't as hard as Rails 2 -> 3. You'd have a better point if you mentioned migration from Angular 1 -> 2.