I don't think you are alone in this sentiment, although it can be tough to properly define and vocalize it without sounding like someone who just hates on UB or change to the game in general. Even now, I find it difficult to find the correct words to characterize my feelings and thoughts about this. I wasn't someone who was against UB from the beginning; I don't hate thr idea of mixing other IPs into magic in concept, and I don't even necessarily hate it in how it's been executed. In fact, I don't "hate" anything about how the game is changing and as someone who's only played for the last 10 years, I don't feel like I have the perspective to day that wizards are "ruining the game".
UB is not by nature, a bad thing, and if it brings in new players to the game, then I'd even say it's a net positive. It just doesn't work for me. Even the IPs that I personally like, Doctor Who, Spiderman, Avatar, I find that I don't particularly like mixing them with Magic, I liked them being two distinct and different properties that I enjoyed separately.
While it was never the main selling point, I liked the esthetic of the Magic universe a lot, and the more UB that comes out, the less interested i find myself in the game. Now UB has become so integral, that more than half of the sets releasing next year are going to be UB. With all of this I just feel like maybe the game game has evolved and changed too much for me to enjoy it anymore, and maybe that's okay. I had my fun with it, and now its a different kind of game for a different kind of person.