Similar situation myself.... A few years I signed up for 3 month for ¢99 and ended up buying a pair of Audio Technica m50x's and got hooked, had them around my neck all year round while I was in school and since then have built up quite a large library.... I had a notification many times saying I reached the limit of songs to save offline, thankfully they've upped that limit recently.
I've tried apple music in the past & what a complete disaster the UI is compared to Spotify nevermind all the bright white space but things just are un-simplified for no reason.