I think it is voluntarily weighted more heavily towards time than upvote compared to other sites like reddit. The reasoning being (I think) that it allow more diversity and less “snowballing” where the most active user just arrive first, get the upvotes, and stays on top. Effectively killing the possibility of a late very pertinent comment to ever climb up.

I think this is a very difficult equilibrium to find, and it has serious implication on how discussions are built. But I really think Reddit has the opposite problem. Come to a post a few hours/days late, and you will never be heard. I create FOMO and pushes user to come back often. This is to me a business model for sure, but not the best way to organize online asynchronous discussions.