Almost everyone uses Google for search. Yes that includes videos using the Videos search tab
Of course, there's Google's own YouTube. It's the second most-visited site in the world, next to Google, and is the top platform for videos.
Microsoft's answer to Google is Bing. What's good about Bing's own video search is that it's optimised for mobile usage, plays videos directly from the website source, and allows searchers to easily find paid video content.
It's the second-largest video sharing platform with more than 300M users.
Aside from allowing users to search privately, DuckDuckGo also has a video search tab which also lets users switch between different countries, giving different video results.