It's practice and it makes you better!

I’d be curious to hear of a time when it paid off and one when it didn’t it. And about the kind of stuff you do.

I’m rather preparing to reinvent the wheel a little bit, as a technical person albeit one who does not code.

I feel like doubling the workload is better than quadrupling the size of the project inheriting a bevy of features and tools you likely won't touch at all. Sure it's stripped out later (ideally), but I like less bloat and that includes during dev when I might have to dig through 3rd party code with its own conventions and standards packed into a 'source available' library with potentially dogshit or absent documentation.

Also yes, it's good practice