I think there are multiple martial arts which are not useful in a real life setting, mostly the ones where there is no sparring and/or the techniques are too. With that said those martial arts have their use too, they can teach you discipline. On the other hand something advertising itself as self defence while it is not effective is fraudulent.
Ironically, the martial arts which don't advertise themselves primarly as self-defence (combat sports) are usually the more effective for self-defence.
from Asian TMA I think judo, muay-thai and tkd can be useful in real life.
from modern sports and martial arts boxing, full contact karate, kickboxing, sambo, wrestling, bjj, mma (if we take it like it would be a stand alone sport)
of course I don't know all the martial arts and combat sports in the world so there might be more than that and I was only talking about weaponless sports and martial arts here
idk about krav-maga, I heard it can be effective if people who really know it teach it and not frauds. The "Israel military using it" reasoning might be overused but it still has to mean something, I doubt that they would teach horseshyt to soldiers whose life is pretty much in constant danger so I'd rather count it as useful. Also it contains no needlessly long and complicated techniques, they keep it tight and quick. It might be more effective in close range situations where someone try to rob you with a weapon than in a straight up shooting the five with one person or more situations.