I’ve done Krav for years, and while the principles are strong the lack of sparring makes it nearly useless in most real combat situations. For example, we’ll drill kicking someone in the groin repeatedly on pads but ignore the fact that it’s actually really, really hard to land a kick to the groin of a resisting opponent. I’m glad that I have the striking experience I’ve picked up from Krav, but I’d trust my jiu jitsu training way more in a real fight.
In the real world, if you want something really effective without any pretensions to being a sport or an art or anything, do Krav Maga.