With all due respect, when have the stock apps ever been good enough on any OS? I spent 20 years using Windows, and the first thing I did upon getting any new desktop/laptop was immediately go and grab a bunch of apps that I needed. They weren't necessarily the "best" apps, either; my old Windows 7 laptop is still running Winamp as my music player because I've used it since 1998 and it still does what I need it to do.

One's preference for programs is really a matter of personal taste. You can try to make the stock programs "suck less", but I doubt you're ever going to really eliminate the need for third party programs. Distros like KaOS (KDE with all-QT apps) have tried, with limited success. The best thing any distro can do, IMO, is to have an extensive App Center and use a flexible packaging format such that it encourages more apps to support that format.

Still using Winamp as well.

At work, people get awed all the time - "wow, is that Winamp?" :D

And I keep thinking, what the hell are people using these days?

Spotify, Google Music, Apple Music, Pandora?

Before I had to worry about space and moving my music around. Now it's on every device. Has all my playlists, all the music I listened to + discover new stuff, friends can send me songs I might like, can even download for offline if I'm worried about not having internet, etc.

It's been a much better solution than playing everything in Winamp which I used forever or iTunes.

I was about to answer VLC and then I red your answer and realized I'm lagging 10 years behind.

VLC is one of the best open source programs ever written. I use it on mobile+notebook for video and music (320-encoded files on a 128 GB SD card). Youtube/many other apps are just not OK in quality.