Maybe in the much later stages of their lifecycle but probably most if not all JavaScript frameworks start to empower developers seeing as they are made by developers.
[1] https://blog.risingstack.com/the-history-of-react-js-on-a-ti...
[2] https://medium.com/@sjarancio/reactjs-a-brief-history-3c1e96...
[3] https://medium.com/the-startup-lab-blog/the-history-of-angul...
[4] https://medium.com/@andrewchall92/how-jquery-was-born-a-brie...
Now if you have written your own applications nearly 60-80% of it executes outside the browser even when the only interface and use case is in the browser. The current common use case for these frameworks is that most developers cannot write original software and when they try they either fail, with plenty of face-saving excuses, or just create something that looks identical to their favorite framework. This is the primary problem these frameworks currently exist to solve for.
It most certainly is not.
It’s really simple. You can write an original application in your own code or you just can’t. I don’t care about all the excuses, because it just isn’t that challenging. It’s not for everyone.
I would never hire you and people with that purist of a mindset.
This is exactly what you're doing. You're seeking the convention of building your own over the measure of valueable developer time
This is insane goalpost moving. What defines an original application? Do I have to write the entire browser? Do I have to write the JavaScript engine? Which JavaScript version am I allowed to use? Can I use TypeScript and transpile?
Software engineers are called such because they use the tooling available to them to create something original. It would be idiotic to not take full advantage of available tooling to do that.