Why classify people as “friends” or “professional associates”? Why bother with picnics *and *banquets? Why not treat everyone the same in all situations? Is that what you’re asking?
As to the benefit of casual - isn’t it nice to be able to relax and kick back with those close to you as opposed to maintaining an artificial formality expected in business settings?
I think the casual/formal divide derives from the idea that people wore their best/cleanest clothes to church on Sundays, and kept their other clothes for the rest of the week.
Somewhere along the line, there became a class divide involved- middle and upper class people wore suits, while working class people tended to have the clothes on their backs. So “formal” type clothing were a sort of low hurdle to keep the riff-raff out of certain places, events and professions, which is still the case today. You can’t show up to many restaurants wearing a cowboy hat, tight jeans, and a western shirt, even in Texas.
The church aspect still exists in that for a great many people, myself among them, one of the primary times I wear a suit and tie is at weddings and funerals, both of which typically take place at churches.
I don’t agree. In decades past, when people dressed more formally every day (even to go to the movies or to go shopping), every man, rich or poor, owned one or more suits. Even the “riff-raff” could manage to dress up.
Fun? Heh. I do my very best to just order everything online so I don’t have to have any ‘fun’.
I do have a good friend that seems to enjoy shopping. But my wife is more like me. Find our where it can be bought, and go buy it. I’m rarely in a store for longer than 15 minutes.