At one point Mozilla was literally selling a VPN subscription. That point is now - you can go buy one today. https://support.mozilla.org/en-US/kb/what-mozilla-vpn-and-ho...

You can even donate money today: https://foundation.mozilla.org/en/donate/ From memory, Mozilla's spent years trying to get donations through asking people nicely and in relatively unobtrusive ways in-browser for years. You can even give monthly - a subscription, if you will.

Not only have they tried both donations and subscriptions, but their efforts have been resoundingly ignored. To the point where you are far from the first person to fault them for supposedly choosing to not do what they demonstrably do.

Perhaps people suggest that donations and subscriptions don't work well or reliably because there's history showing that.