This post actually made me look for a solution and I found one! Solution to opening tiktoks without using tiktok app or site, not how to stop ur friends sending u garbage.
It made me think... mpv player can play basically any link you throw at it (thanks to yt-dlp), and we also have mpv on Android, so why can't we do it there as well. And sure enough, I found this https://github.com/mpv-android/mpv-android/pull/58, someone baked yt-dlp in mpv for Android, making it possible to open link in mpv (share >> play in mpv)