Q: Do search engines other than Google even matter today?
A: In the United States Google controls about 65% of the search game. Bing (Microsoft) comes in around 24%. Yahoo! shows up in third place with about 11%. Yahoo! is now owned by Verizon. When you drill down on mobile search Google leads again with 93% market share.
My experience has been that if I optimize for Google my rankings with the other search engines usually show up similarly to Google. I tell people “If you want to catch more fish, fish where the fish are!” Most of the fish are at Google.