Even until the last few years on Windows, codecs were a shit show. You could download codec packs, but it was pretty hit and miss. VLC was amazing - it would open everything, audio just worked, and subtitles just worked.
Yeah. And ending up playing a game of "useful or malware"
That's true even today, maybe I'm getting old and I don't play much with other tools like I used to do, but VLC is the only one that always "just work".
CCCP has worked great for me on Windows for the last 10+ years.
CCCP was amazing when it first came about. The last time I wanted to watch something, though, KCP was recommended over CCCP. Things are forever going to be a bit of a mess with playing anime since there's a long tradition of being on the bleeding edge of encoding.