You are thinking like a software engineer, not a product manager or owner of capital.

If any of these companies is able to extract monopoly profits without fear of competition undercutting them or government/legal intervention, they will.

Right now all 3 are competing fiercely to win the hardware rental market, but this may not be the case in the future once the market matures, and they may raise prices to match leaving costs (as parent comment pointed out) if they can lock customers in.