Angular, React, etc. are nothing but a bunch of pre-written lines of code that does data binding. Quality lines of codes with a lot of candies, but in the end it's only a bunch of JS lines.
There are no obligations whatsoever to keep your project cutting edge and even less of reason to migrate to a more popular framework. It's not as if browser support for Angular 1 would stop.
It is, but you have to balance it out. Updating an entire app to a new major version (without backward compatibility) simply to use let's say a new API wrapper or syntactic sugar is a waste of time. If the app works fine, there's no need to migrate.
There are no obligations whatsoever to keep your project cutting edge and even less of reason to migrate to a more popular framework. It's not as if browser support for Angular 1 would stop.