If you’re looking for tank mates, I have some rosy red minnows with my goldies that go great and look wonderful. But ya, Goldfish are like cows they constantly graze the bottom of the tank looking for food so you don't have to have a scavenger.
i had two goldfish in a 10 gallon for a while and they got big and they just made the tank nasty and extremely dirty all the time, my uncle gave me his 55 gallon about a year after having the goldfish and it had a pleco and i put my goldfish in it and it also had some kind of barb. but the goldfish got almost a foot long in that thing lol they were huge.