I can’t speak for anyone else, but I find that my usage of the web is more like a mind map. In other words, a tree or a directed graph.

I open a tab to accomplish something. From there, I reach out in some primordial/human-brain breadth first search of links in order to accomplish my goal, branching off of branches and coming back up to some parent only to branch again.

For people like me, a linear set of tabs is indeed the wrong abstraction for the way I use the web.