Poker requires skill but there's still a major amount of chance involved. Removing the chance and conspiring against a single player turns the game into a show. You can set up cheap wins and expensive losses. It doesn't really matter how well the other players win or lose because they are all on the same team, you're the only one actually losing any money.

I remember as a kid, I'd play battleship with my siblings. I was really good at it, they were not. They hated when it was obvious that I let them win but also hated when I beat them badly so I found a way to make the game go longer. Often we'd play on a glass table and I'd "drop" a piece so I could peek under the table and see where their pieces were. I could get a hit and then miss many follow up shots to slowly destroy their ship and give them more time to find and destroy mine. They'd gloat over their hard-fought win but I'd just smile and beat them for real next round. I could have done this without peeking but I wanted to make sure I didn't accidentally play too well.