I just can’t see any use I’d have for a tail. If it were long enough, it could help with balance, but it’d probably just get stepped on. Plus, all my pants would have to be altered. And it would make playing poker harder because it would wag if I had a good hand.
And I’ve never seen my dogs or cats use theirs for anything practical, either. My tail-less Manx cat had no disadvantages vis à vis his tailed housemates.