At max charge they deal some of the highest damage per hit out of any dino in ARK, however this can only be effectively used when ridden so keep that in mind.
They have utility in fights against the Dragon as they can deal considerable damage when ridden by a player.
If you are on a pvp server(pve works as well), and you're raiding someone, try to use the rhino's charge attack. If your opponent has a rex, and you hit it with a full charge meter, it will be an instakill.
The wooly rhino is a great tame I got a 150 perfect tame and just used it in a raid and it took down 3 Rex's and with the help of another rhino we took down a giga really recommend this dino
Get a male and a female rhino breed them until you get around 500+ melee damage, with 100% imprint it almost always rages gigas with one full charged attack.