Go look at something such as a phpbb site where topic ordering is driven solely by 'bumps' - the most recent topic to have a comment gets bumped to the top of the page listing. You'll find they rarely have any worse ordering of content than voting systems provide. In my opinion it tends to be simply superior. It also avoids the huge problem in point based systems of requiring some 'parallel universe' /new stream that only a tiny and biased minority ever view.
But voting systems drive "engagement." One intuitively surprising discovery is that downvoting users tends to drive them to comment more, frequently with lower quality posts following. I say 'intuitively surprising' because it seems counter intuitive, yet if you've spent any time on point driven message boards, including here, you see the constant stream of little tit-for-tats as a downvoted user (or two) engage in an ever lower quality of 'debate' in some isolated thread. As for upvotes it goes without saying that that little micro-shot of dopamine is what's built, and arguably sustaining, the social platforms of today.