Pokemon Sun and Moon launched back in 2016 and included the intriguing concept of Ultra Beasts, which were the 7th generation’s dimension-crossing creatures. Fast forward to today and we now have background information on their unusual design. The Ultra Beasts were created by Pokemon Sun and Moon designer Yusuke Omura who had been testing out designs for new and unusual Pokemon, but they were initially rejected by Game Freak art director, Ken Sugimori. Thinking that the Pokemon designs should be put to good use they decided that they would use them as the Ultra Beasts.
“I designed the Ultra Beasts by recalling some of the designs I made which were rejected by Mr. Sugimori, and I decided to deliberately use the very reasons for why they were rejected and base the artistic direction of the designs on them. So in some way, they’re like a manifestation of my own resentment– pretty scary.”
“Of course, this doesn’t mean that I hate Mr. Sugimori or anything like that.”

This does explain why Ultra Beasts never felt like Pokémon, because they are Pokémon rejects. That actually fits with their lore and different classification so I like that.
I actually liked Sun/Moon but Ultra Beasts definitely felt off. It was kind of understandable because they already jumped the shark by having deities and a literal god pokemon so… I guess that mean that had to go multiverse pokemon, as modern fiction seems to do now.
I still think it’s entirely possible they will do fusions at some point. New Pokemon fusing with popular Pokemon, and then Pokemon fusing with legendary pokemon, and then legendary pokemon fusing with other legendary pokemon and then… maybe… just maybe… Humans fusing with Pokemon.
This is easy to predict btw because Digimon has already done all this before.
My favorites Are Guzzlord, Naganandel, Xurkitree, Nihilego and Celesteela.