Android, and other mobile systems, are made for low-powered hardware. They don't actually do as much as we think they do, but rely on the cloud for a lot of their smarts. Send the raw data to a server somewhere, and get the answer back.
I use an app to broadcast the raw camera to a desktop web browser, and I put that URL in OBS's browser source as a non-critical "special interest" shot, but that's about all I'd expect out of a phone or tablet. Raw camera, sent straight out, with no processing whatsoever.
There are apps that already do that, and you really can't do much more anyway, without shipping it off to a more powerful platform. So there's no point in having OBS on a mobile OS. Put it on a laptop at minimum, and use the phone just for the camera, and maybe an internet connection. No video *processing* on the phone, which is really what OBS is for.
