Lol I was writing my answer and it was becoming a novel.
I think procreate is absolutely amazing and totally good enough if your goal is to learn digital art regardless of platform and to learn art fundamentals in general. That said, if down the line you think you might want to work in a team as an artist (for example a concept artist, character design etc) then I think it's definitely worth investing some time and a monthly subscription even if only for short bursts while you are learning the app. If you are sure you won't use it down the line, then sure, procreate all the way.
Also, if you are interested in working some of your digital art on PC there are other options as well. Clip Studio paint goes for super cheap various times a year when on sale and for all intensive purposes is still a one time purchase for a fully featured app, but the overall workflow is very different imo (you really gotta get familiar with the brush settings for example) and another great option is Krita which is free, and surprisingly good.
cheers
