I hardly use it, though, because I usually have < 100 open tabs, not thousands like others have. I identify tabs by their tree structures (parents, children, siblings tabs) and the prefixes of the titles, whose lengths don't depend on how many tabs opened, because the tabs are arranged vertically.
As for history, imagine you're researching a topic and have gone through fifteen search results, decided three of them were relevant, and closed the others. Your history is polluted with all fifteen, whereas this tab search will directly return you these most relevant pages only.