Different denominations have different traditions. Christianity is not a monolith and has split many, many, many times.

My experience is that the more separated the church is from the oldest denominations, the less likely the priest or pastor is to wear "traditional" garb. The church in the picture is some flavour of southern evangelical, and so is pretty far removed from Roman Catholicism.

I grew up in a reformed Calvinist tradition and the pastors always wore suits. In later years, younger pastors would even ditch the jacket in the summer.

Situational as to the church. In my experience the less overtly church-like the house of worship, the less likely the pastor is going to dress like what we'd consider a pastor. Football stadium/theater mega church? guys lookin' like a used car salesman. Full stone with the statuary on it? Dudes fit is gonna be immaculate.

A suit seems like good attire for a showmaster and/or business man

On the first point I had a thought about this the other day. My grandma told me we're supposed to wear "our best" to church and someone wearing jeans would wind her up big time. Then I thought, "Uh, none of these clothes existed when Jesus was alive. If anything we should wear tunics."

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.