I've probably got about 60 open across two sessions right now, and this is typical or lower. It's as simple as having a queue of things to get to, plus groups of tabs represented in-progress research on some topic. It's especially useful given tab-sync across devices. It's not a workflow for everyone, but if the benefit of having easy access outweighs the intangible mental cost of a zillion tabs, it can work very well.
