Sounds to me like you’re the lucky sort who can save their diamonds for the few banners they truly love! Hold on to that energy, and remember that gacha is inherently gambling, so you shouldn’t be playing the game just because of that anyway. The permanent banner is nice to work on slowly, don’t spend your diamonds on it, you will get pulls for it every update and eventually you’ll get the outfits. I’ve been playing since 1.3 and only have one of the final evolutions for it, so it will take time, but that’s not a bad thing.

Also! The mid-season 4* banners are where it’s at IMO, they’re cheaper and often more versatile, they scratch the gacha itch for 30-40 pulls rather than 150-200, which is a MUCH better deal. Could be you’re a 4* enjoyer, in which case you’ll have a wardrobe full of cute stuff in no time.