Take everything with i say with a grain of salt/do some searching to get more specifics of what I say, its been years since I’ve really considered myself properly Catholic and a lot of what I learned is a bit rusty.

It depends on the flavor of Christianity, Catholics and some Protestant denominations that are still traditionally pretty close to Catholics, like the Anglicans, use the all black outfit with the Roman collar, that black collar with the white tab for their day to day outfits and the wear specific robes and garments when performing Mass.

I’m not sure of the details of the various flavors of Orthodox, but the bit I have seen tend to also use the various robes and other garments.

Some flavors of Protestant tend to focus on their leadership being part of the people and being in service to others (and actually do a lot of community service) tend to wear fairly plain common clothes.

And then the big Protestant mega churches that operate more like tax havens than actual ministries serving the community, tend to wear the nice suits and fly in their private jets.