My fish are just as much as my pets as my dogs and cats are, hell they're my children. They all have names (except my community tank of little freshwaters) and I spend just as much time with them as my mammalian friends.
Spoiling them to ****, feeding them a variety of food, setting up awesome aquariums for them etc is the hobby. Every time I have money I run to different LFS to buy some stuff I don't need atm but will maybe, possibly someday in the future. My fish keeping hobby is borderline obsessive tbh