Many (most) of the companies you've mentioned have existed LONG before Google was around in any public capacity.
Its also important to note that there are a lot of things Google can NOT do that other search engines CAN do (like compounding search queries, something very common, if you use the Internet for real production research). They're good, they're fast, but they're not the best.
This article has some great content about those "legacy" search engines and where they've gone.