I haven’t used XAMPP in a long time, but I wouldn’t be surprised if phpMyAdmin used it.
Yes, there could be a great many folders / files.
That’s the beauty of OOP. Instead of a few mega sized files everything is it’s own thing.
That can be a problem with OOP. Everything is it’s own thing. It can be a major pain getting all the dependencies together
Personally, as long as they’re working and I was unsure if they might be being used I would leave them be and experiment with using some of them.
There are some very amazing PEAR extensions. Just about one or more for just about anything you may be interested in.
https://pear.php.net/packages.php
Some have been deprecated, some are in want of a maintainer, some have long standing issues.
So if you have a good bundle put together you may regret deleting it later.
Unless of course you’re hurting for disk space.