People having more than 1 bank

So I’ve realized people have multiple different bank accounts and was wondering why ? Is one for spending , the other for bills and another for savings ? I have chime bank and I use that for everything then I have a credit union saving account but I’m tired of chime and trying to find a real bank to do my banking with . I’m thinking do chime for all my direct deposit (because I get them 2 days earlier) credit until for savings and another bank for bills and personal spending