I use side-loaded 4K Video Downloader: https://www.4kdownload.com/products/videodownloaderandroid-4.... Not a regular viewing client though.
edit: If I end up trying this out it will have to be on a separate user profile because of the permissions.
Personally, i just install termux and yt-dlp. Admittedly, i am on a rooted device, but i think some additional tooling is available to give termux access to the shared user storage area.