really which part? that ui where it switches songs if your finger grazes it even slightly? and starts over completely when you try to flip it back, forgetting where you were? the loud non audio adjusted ads?

Presumably they mean the part where it gives you easy access to a huge amount of music all in one place (unlimited and ad free, if you pay for a subscription). Most of the time I'm listening to music in the background so the UI isn't really much of an issue.

The part where you don't need to spend hundreds upon hundreds on CDs and can listen to any music wherever as long as you have an internet connection?

I'd say with very few features I miss from Spotify, that yt music is simply a better platform (even more so with owning yt premium)