It's killed the educational software market. My organization spends much less on software than we used to, back when we could purchase it outright.
When was that? Educational software (especially administration) is such a small market and requires such extra expense (mostly yearly reporting changes) that it's been software + maintenance contract since the 1980s at least.
We tried selling software outright for a few years and found mot districts actually preferred maintenance contracts. It made costs more predictable for them vs. optional upgrades they may or may not want (and may or may not need).