My bet is that Angular pushes for using TypeScript too much, which makes you wonder where to start. On the other hand ReactJS & Vue work with TypeScript, but are not designed to embrace it.

I've seen lots of questions about Angular on StackOverflow which should be classified as TypeScript questions, since they have nothing to do with Angular itself. I guess that's the confusing and non-attractive part of Angular.

TypeScript is awesome and I love to use it, but some of my clients ( freelancing ) don't want me to write TS code, since they are afraid that it will be harder to find a substitute and will increase complexity - both are reasonable arguments.