Quick shout-out to Grayjay: An app to watch videos on any platform - reducing the power of individual services. The Software is open-source and can be found here: https://gitlab.futo.org/videostreaming/grayjay
I will test this out for myself and hope someone here finds this useful.
Sideloading on iOS is free but a total PITA. There is little incentive to build an app for such a small userbase