If you watched the all star game then you would know that sometimes it does matter.
I have seen games where two superstars are going at it very competitively trying to win the mvp award (durant, melo, lebron). These guys care about their career resumes/accolades and want that recognition.
I have seen games where it was close at the end and all players on both teams took it very seriously/competitively and played defense and tried to win the game.
I remember an all star game (I think it was the rookie sophomore game actually) where kyrie irving and tim hardaway jr (iirc) went back and forth at each other with each guy trying to stop the other one and not being able to. (It was pretty awesome to see those two guys both on fire at the same time going at it)
Plus watching elite athletes fly through the air for amazing dunks is very enjoyable for many people.... Hell I have had fun at actual games just watching guys in warm-up going through the layup lines..... Definitely nothing being played for there but that was where I first realized that Rodney hood had pretty damn under-rated hops. (He put on a show at his rookie year jazz scrimmage on the layup line)
Pretty much this.
Yeah, a good amount of it is just them jogging up and down the court jacking shots, but cool things happen during the game. Little battles happen where players try. Crazy dunks happen. Then when the game actually gets tight in the final minutes, they really start trying. I mean, it's not a great game, but it is cool IMO.