There are strong network effects in many digital markets. In these cases, given enough time, it leads to a monopolist employer in that market. Even in cases where there are a few firms competing (e.g. Google and Apple), they have incentive to form a cartel through 'agreements' on hiring practices (and there have been documented instances of this). The natural way for software developers to avoid being exploited, in either scenario, is to form a labour monopsony...