How long before this becomes a standard required by authorities??
The MP21283X, MicroPilot’s triple-redundancy (3X) autopilot, is now available. Although 3X technology is established within the aviation industry, 3X autopilots are a new addition to unmanned aerial vehicles (UAVs). The MP21283x contains three robust autopilots to overcome a multitude of hardware failures. If any one of the three autopilots should fail, the remaining two take over. An additional mechanism oversees these three systems.
I agree with your point, but as Ersin has said it's about redundancy in a system. I believe in many if not all commercial aircraft there are a number of duplicated systems which allow for a failed circuit to be isolated and a secondary circuit to be enabled, this level of back up offers increased safety in the event of a component failing in a system.
If there is something wrong on power source you cant do anything ofc.
I have been thinking about this also, I think that the minimum you could use would be three, if one were to "fail" then you would need the confirmation from another source to compare, if you only had two, how would you know which one was producing the correct information.