There is a rub to this too however. In a pay to upgrade model you are incentivised to stuff your application with features and also need to support old versions indefinitely if they have network components.

Granted in 1Pssword case, their classic app would not have stopped working without upgrades. And to my knowledge it should also still work? I have since switched to the subscription model but I have used the old paid app years after they have switched models.