I'd say it depends on what uses it, tbh. Of course if it's something with low HP using it, definitely not, but from with lots of HP in general, probably. I don't really think it has much use though considering it's one-time and that you can't revive Pokemon in battle, and sacrificing one Pokemon just for that purpose seems kind of useless when you can take out threats with other methods. While Memento, on the other hand, makes sense, since you're actually "doing" something to the opponent (really with this, you're not even "attacking" it's more like a murder-suicide tbh) and... Final Gambit just seems like a waste of a Pokemon imo - and risky too, having to avoid being attacked first and all. ;x