This has allowed smaller software applications such as Sketch, The Affinity Suite and Capture One to grab marketshare. I think Sketch’s current business model is perfect. Customers pay for a year of updates. If a customer decides not to upgrade, they stay at the same version as when their license expires.
I’m certain Adobe has made a good amount of money in the short term, but they've forfeited a monopoly. I’m more skeptical about their long-term business.
EDIT: Updated for clarity.