It is viable but its mechanics are kinda difficult to take advantage of. The best user of it is Tyranitar in gen 8 OU because therian Landorus tends to intimidate it, so you can just delete flying lion from the game with just one move, assuming it is the spdef set and not physdef.
In the end, if you wanna use it, make sure you can take advantage of its damage mechanics otherwise you might as well use the brainless spam move in knock off, or crunch which has a slightly higher base damage and can drop the target's defense stat
