I've tried many other similar plugins/apps, and in my experience DroidCam OBS is the best and most stable! If you need to connect your Android or iOS device with OBS, then look no further.
I've been using the Pro version for over a year, along with several Android (OnePlus 5T, OnePlus 8T, Redmi Note Pro 8) and iOS (iPhone 5s, iPhone X, iPhone 12 Pro) devices. I usually use any two devices at a time.
I get excellent video quality and minimal latency over a USB connection (I don't use it over WiFi and I don't use the audio, so can't comment on the same).
Also, it comes with a nice remote control feature that docks in OBS. The devs update the plugin pretty frequently and have been improving functionality and quality over time.
PS - while it may sound like the devs have paid me to gush over this plugin :) They haven't :(