Ask yourself the following questions:

• Why do I need to learn a framework?
• Which framework should I learn? (as stated in your post: Angular, React, or Vue).
• When you decide, is the framework suitable for the project at hand? (if you have a project in mind).
• What is the learning curve of the framework?
• Are there enough learning materials on the Web?
• If not, is the framework documentation easy to navigate?

In my opinion i prefer React just for the easiness sake. It's also nice to use it on the server side if i'm just testing and need to render some HTML elements to a string. For me, Angular has a pretty big learning curve especially with the different services and modules.

It kind of depends where you want to work. Big companies prefers react and angular. I hate Facebook and despise Google. I like to work on interesting projects in smaller teams. Vue.js, driven purely by community, was a clear winner for me. I also use Svelte in my latest projects. Having the chance by using the framework to kind of interconnect with the mindset of people like Evan You, Rich Harris and the people around them helps me to grow.