They certainly don't have control over the military in the "Napoleonic supply officer coup" way. Diversion of funds and corruption while bad cannot lead to an outright coup. Gear is a long term thing for securing loyalties of the men holding the guns. Money alone wouldn't work well - the government has more and gave them everything they have. The high level of complexity and specialization of advanced military gear while favoring them fiscally also means that they wanted to go full treason and use their manufacturing capacity to equip an army covertly they would be at massive disadvantage from lack of skill even if they had enough legitimacy that their employees wouldn't just nope out the moment they did something so crazy. That and fear of facing serious charges.
That bit aside the reason is that corporations do a better job at it. The US navy once had their own manufactury - they quit doing it when private industry could get them better bang for their buck. Also methods of social arrangement which are helpful at a corporate level for their domain would be disastrous for governments.
Having competing monopolies of force isn't a stable situation for instance. Squabbling divisions drawing from the same resource pool are bad for serving the root cause. Corporations have seperate resource pools in competition without the same set of problems.
A government would have a Morton's fork for its own manufacturing. If they had only one division they have the same disadvantages as a monopoly. If they have multiple for the same niche they have the same issues as above.
That bit aside the reason is that corporations do a better job at it. The US navy once had their own manufactury - they quit doing it when private industry could get them better bang for their buck. Also methods of social arrangement which are helpful at a corporate level for their domain would be disastrous for governments.
Having competing monopolies of force isn't a stable situation for instance. Squabbling divisions drawing from the same resource pool are bad for serving the root cause. Corporations have seperate resource pools in competition without the same set of problems.
A government would have a Morton's fork for its own manufacturing. If they had only one division they have the same disadvantages as a monopoly. If they have multiple for the same niche they have the same issues as above.