Yea there's a lot of things it could do one of, but those things are still trading a high level spell slot for the thing (or part of it) that someone is doing every round without consuming anything but their action. I think that it's versatility doesn't come up often because it's such a high level spell & it competes with everything else that also uses concentration. If it was fire & stack something else 3.x style instead of concentration it's versatility could really shine in spotlight grabbing ways when combined with things like web/slow/haste/wall of x/etc, but using concentration means it needs to be able to really grab some spotlight time & a selection of "decent" "not bad" "versatile" "not spectacular" effects don't do that2d6+5 is only if the target is being grappled, which also makes it's movement 0 - a decent effect.
Assuming the hand just punches damages is 4d8 - avg. 18. Not super amazing, but not bad either.
Plus the hand has several effects it can do, making it decently versatile - even outside of combat in a pinch.
And that's really the point. Damage is fine, if not spectacular but it's really versatile too. Kind of like the wizard!