I think that google thinks that it's not worth it. They could believe that videos don't have as much relevant information as text. Or if videos do have more inf

I think that google thinks that it's not worth it. They could believe that videos don't have as much relevant information as text. Or if videos do have more information, it's not worth it to try to spend so much compute for it. Plus large scale retrieval of video information is pretty challenging (even for them). Facebook had to create a new framework (FAISS) to solve this problem. So I presume it must be pretty challenging. But on a short scale, they already do this. For some queries, in the search results, they show a youtube link which automatically goes to the relevant part of the video.