It gives you different perspectives.

I've only been on a handful of program committees but spent a couple of years reviewing tech books for a publisher. You use the word 'responsibility', yeah, hold that. Having to look hard at what people have done, critically, is really challenging but very educational. It may be things that you are not sure about, so you have to get yourself up to speed to do it justice.

It can be a nightmare - borderline cases are painful.

Seeing what works and what doesn't, for the subject matter, but also for the write-up, your main interface.

I'm not in academia so it isn't necessary for me, but I'm pretty sure I'd make a better paper now than before reviewing.

Also CV :) .