It's who-you-know, not what-you-know. I should mention, by convention, you do not get to see the letters of recommendation yourself, so you're at the writers' mercy. (At least in my field, mathematics; others might be different.) Papers and conference talks become harder to do if you're no longer affiliated. Your abilities will shine through if you're Albert Einstein, but the 99.99% of "rank and file" professors don't need to be Einstein.

I'm not intending this as an indictment against academia. They're faced with a hard problem: many more candidates than job openings. They couldn't possibly do whiteboard interviews like in software, just because of sheer logistics. I don't know how academia could do it differently. Software can do it better because there's a LOT more money in software.