Svelte has always looked so promising, just what I wanted. But my fear is that if I ditch Vue and jump to Svelte, it will do the same thing as any other framework did: become a monster and cause problems with all my dependencies.
So I'm staying with Vue.
I can't claim that that upgrade was painless, it took a few days with an app with > 10 pages, >20 custom components and I had to push ahead with re-writing a 3rd party component or 2 that was only vue 2 at the time (honestly I should never have used them in the first place. reap what you sow). But build times are faster, my bundle size is a lot smaller, I'm really pleased with the new features, and I'm a building faster as a result.
Vue 3 was designed with large complex projects in mind. Vue 2 is probably easier to grok when starting out or for small projects but the functional modularity, typescript integration, and reduced boilerplate with 3 really starts to show in large projects.
I did it slowly over a year and besides having to wait for some dependencies to catch up it was mostly painless.
Although the biggest pain-reduction was getting to use Vite instead of Webpack (shudder). The build tools not sucking is so critical when doing front end dev.
But in hindsight your comment (which could have been mine a few years back!), is really funny. Basically, are you staying with Vue because it's the monster you know, or why don't you fear Vue becoming a monster? :)