Infra cost isn't as high. A company reaping a billion in profit yearly would be spending around 10-20M only on infra (my previous company had 100M users and this is the estimate from that). So a nonprofit would just seek funds for infra and dev cost. Of course, it all depends on the kind of platform. But how about people embracing FOSS? Switching to Linux from Windows, to LibreOffice from O365, to GrapheneOS/LineageOS from Android, to Firefox from Chrome, that sort of thing. It'd be a drastic blow to the revenue of these companies. What people used to pay for earlier, they'd not be paying anymore. Maybe this would translate to other things like the cost of laptops and mobile phones rising because manufacturers will no longer be incentivised from software companies.