Then you realise this is what a lot of people spend their working lives doing, rewriting frontend code in a different framework for no good reason other than they want to.
Yeah, no native tools ever get written in different languages and frameworks. Or is it only not acceptable when Front End developers do it?
Personally I've never known anyone do this for any other reason but educational reasons. When I wanted to learn React, I copied other websites in React. I do similar things when I'm learning Golang, or C, or any other language I'm interested in.
I’m not sure what the go/C equivalent of “Ugh, you’re using jQuery? Time for a rewrite” is. It happens a lot more in frontend land than in the rest of the developer ecosystem.
You're describing switching to a different language. There's plenty of that going around no matter what language you're using. But I don't recall once seeing anyone decide to rewrite something in the equivalent of a different C "framework". There's certainly a lot less of that outside of frontend development.
That's because if you want to write for the Web Platform, you haven't been able to switch languages; you were largely stuck with JavaScript for decades.
Contrast that to writing for the Windows Platform--you could easily choose one of many languages.
Personally I've never known anyone do this for any other reason but educational reasons. When I wanted to learn React, I copied other websites in React. I do similar things when I'm learning Golang, or C, or any other language I'm interested in.