Tab requires zero effort to learn. It's basically connect-the-dots for guitar and bass.
I partially disagree. It seems to take more effort for me to use tab to figure something out, than to just listen to it. I typically have to do both, anyway, if I'm going to use tab at all. Tab is a last resort. And even then I only refer to sections I can't figure out just by listening. Tab is really not significantly more efficient for me than notation, to be honest.
Granted, I don't play the most complex stuff in the world. If I were to do jazz or classical I would have to up my notation reading significantly. Not much of a worry since I have really have no desire to do either right now.
I guess lack of know how makes things better?