What proprietary video/image formats does Google have? As far as I know all their image and video formats are open, including WebP. Heck, according to Wikipedia JPEG XL was also partly driven by Google.
WebP was only developed by Google or a company Google ended up buying. Yes, the standard is freely available, but there was no collaboration, no open process of asking people's input, etc.
I said nearly-proprietary. WebP is technically open but nobody would give a crap about it if Google weren't promoting it.