Because of the way Bethesda Fallout equipment tables are structured and especially with item wear, everyone is going to look like raiders or worse for much of the game. People will equip the best piece they own for each slot more often than not even if it's a horrible mixture of types. Even though a lot of players will max level the game in the first 24 hours or so, no one will be able to max-out matching gear that fast. It's even difficult in FO4 to put together good matching sets of legendary. And wearing The Dapper Gent is almost necessary.
So while some people may run around in red dresses with Eyebot helmets, they won't be wearing that for much but standing around.
Power Armor may not be as popular as it seems it would due to decay/repair in a multiplayer environment being a lot more trouble than stimpacks + drugs.