Upgrade pricing leads to feature bloat. Sure you could stop at say office 2003 features and then only update it (for free) when you need to fix bugs and compati

Upgrade pricing leads to feature bloat. Sure you could stop at say office 2003 features and then only update it (for free) when you need to fix bugs and compatibility issues with new systems. But that's still work! So your only chance is to abandon the software and reap the insults coming from clients who upgraded to a new Windows installation and can no longer run your software. If there was some realistic ways to bundle software in a fashion that it will continue to run forever even if environment changes, then sure–but your software better not be networked. (This is also where docker and the likes come into play).