From my understanding, the complexity of distributed consensus is partially explained by the fact network zones can be isolated and don't have all information about all the created blocks and transactions. Hence the possibility network forks and the necessity of proof of work.

But what if new networking medium is invented? To simplify, what if all the network participants are sitting in the same room and use radio transmitters in order to propagate new blocks, so that it is not possible or very complex to hide anything?