The paid upgrade model creates some perverse incentives and support headacches. It encourages a company to declare something a major (and thus paid) upgrade0 Ye

The paid upgrade model creates some perverse incentives and support headacches. It encourages a company to declare something a major (and thus paid) upgrade0 Years ago, Adobe used to do this with supporting new RAW formats that came out. it would only add them to the newest Photoshop version when there was absolutely no reason they couldn't add it to the RAW plugin for all versions. This fragments the user base and creates support headaches. If a user has a problem, is it a KP with that version? They won't pay for an upgrade. Are you going to backporta a fix? It might be a little used version. This leads you to having policies that EOL software. Nobody really understands that. The customer gets mad because they paid for the software in 1987 and it should still work. Subscriptions solve these problems. It can create problems too eg: 1. The Adobe dark pattern model of having to subscribe for a year and hiding the auto-renewal and how to cancel; 2. Once again, the Adobe model of setting the subscription price of basically the sticker price you once paid divided by 12; and 3. Requiring you to be online to monitor your subscription status meaning software that should work offline doesn't. The gold standard for a good subscription model is Jetbrains.