Yup, Groove has come a long, long way and now can claim to be among the big boys.
At first, it's ability to play my 38G personal collection (including WMA files) from OneDrive was an attraction. Then it's huge (if not the biggest at 40 million tracks) catalog created interesting (non boring) radios, where I discovered lots of artists.
But now they add both curated by humans playlists (under "Explore") and algorithm derived playlists (from my collection and playing habits) in "My Groove," which makes it equal, if not superior, to other big streamers.
I was a HUGE Spotify fan. But now, Groove meets all my needs.
Got to say, I'm a bit amazed Microsoft did this for a consumer app (given their focus on their heritage in corporate world), but I'm happy!
Keep going Microsoft.