They're the most efficient, for most situations.
While I also like aikido, judo, and karate/taekwondo, they're not so useful by themselves unless you have a lot of experience with them. These arts tend to have a higher learning curve, especially if you didn't start as a child. Whereas, with boxing and jujitsu, you can defend yourself pretty well after about a month or so (against normal people that don't train).
Imho one should familiarize themselves with the basics of all the styles, so take that as you will.