I started playing with Vue in 2015, even wrote an article [1] about Vue which was pretty popular a couple of years ago (it was hosted on Medium then).
These days I'm focused on Svelte. It's faster and lighter, but IMO the best feature is you write a fraction of the code. When I go back to old React or Vue projects I want to cry. Svelte is so much more zen.
OTOH the ecosystem is minuscule so you are on your own. The support for TS and testing is not great either. Svelte is easy to learn but it's not very popular yet. I would understand if someone argued it's a risky bet although I'm building my SaaS with it.
Maybe take both for a brief spin, but my vote would be for svelte. I used vue2 about the same timeframe as you (stumbled upon it while trying to find alternatives to React or whatever) and really liked it a lot.
About a year ago I had to tackle a few new web projects so I decided to give React/Angular/etc another look... and promptly went hunting for alternatives again, and that's how I found svelte. We've got 5-6 svelte-based projects in production now and have really, really enjoyed it.
All that said, I haven't looked at vue3 in depth yet, so maybe it's amazing, I dunno. :)
If you know Vue 2, Vue 3 will be easy to learn, as well. There are some more advanced features you can choose to use if you want, but I guarantee you could pick it up really fast. This isn't an AngularJS -> Angular sorta change.
Also, give it a few more months before building anything non-trivial. Some of the more popular libraries for Vue 2 still need to up updated for Vue 3 (vue-router, vuex, for instance).
Where I live, VueJs isn't even mentioned in any job postings. Large companies still work with older Angular projects, new projects are more often than not done in whatever fits the need.
These days I'm focused on Svelte. It's faster and lighter, but IMO the best feature is you write a fraction of the code. When I go back to old React or Vue projects I want to cry. Svelte is so much more zen.
OTOH the ecosystem is minuscule so you are on your own. The support for TS and testing is not great either. Svelte is easy to learn but it's not very popular yet. I would understand if someone argued it's a risky bet although I'm building my SaaS with it.
[1] https://www.pierbover.com/posts/vuejs-good-meh-ugly/