That stranglehold is made possible by their customers. Every one of their customers have the option to buy Corel (for now - as they're moving to subscription-only later this year) or any number of other graphics editing software, or use the free gimp, krita, etc. They choose not to, because for whatever reason they prefer Adobe. And for a lot of those folks that reason is because $20 a month is much more affordable than $500+ up front. And holding on to CS 5 is fine. I still have CS4 (which I never use anymore because 2018/19 is superior in just about every way), for now but eventually it will no longer function in the latest OS, which you will also eventually be forced to upgrade to when other software you want or need to use requires it, or when that old winXP etc system dies.