Do you run a website where those are significant traffic? It's been a long time since not-Google search has been more than a rounding error in my experience, with the exception of Yandex for Russia and Baidu for China if you have content for those audiences.
Vimeo and Firefox are trying but the trajectory has not been good.
The question was about alternatives to Google services (which do exist in almost every category), not about the share of traffic that websites receive from various search engines. If websites want to avoid being overly dependent on Google then they're going to have to get creative and figure out ways to drive traffic other than search.
Your last sentence is the point: it doesn't matter if there are alternatives which are either unused and so far the only company which has figured out how to out-drive Google is Facebook, hardly more responsive to the rest of the web's needs.
That was the problem: in search, Google effectively has no competition. The fact that there are other areas like social networking doesn't change the fact that if you're a website operator you have to work well with Google even if you can write off everyone else.
Some ad blockers can block Google AdSense.