It's kind of like we've been incurring debt all that time, and the "payments" are all deferred as long as you keep the subscription. But if I drop the subscription, suddenly I don't own any music newer than 2015, despite having paid $1200 -- it was just to rent music from Apple all that time.
Which kinda would be fine since I can afford it and it allowed me to get more music than I probably would have bought with a $1200 iTunes gift card.
But as you pointed out, Apple Music (and in my humble opinion Spotify and YouTube Music) both have modern-day UIs that are a horror show, only getting worse with each passing release. But the only choice is to keep subscribing to one, or rebuild your library at great money or time expense. :(