Krav Maga itself is not bullshit, but most of the places that offer it are.

The main problem is that you can't practice/spar true Krav Maga, because you would seriously harm your training partner. Krav Maga teaches things like crushing testes, gouging eyes or grabbing a brick for an improvised weapon. It makes the assumption of "life or death".

Building off that, the best practice for martial arts comes from sparring. It's better experience with an opponent who is resisting you instead of standing limp while you work through a move in slow motion. I think it was Mike Tyson who said "everyone has a plan until they get punched in the face".

People always ask which one is best, but there's no right answer because every martial art has its own merits.

The best answer will always be mixed martial arts. Cross training allows you to be comfortable in any situation.