This was the “old” subscription model for desktop software. It’s the model most software with yearly updates was sold under (MS Office, Jira, etc, etc) and was basically a yearly subscription (to get access to new versions) except that it guaranteed the developer would be creating yearly releases to make it worth adopting newer versions, while the “current” subscription model doesn’t particularly encourage a company to continue innovating and developing to ensure their products don’t stagnate. The only problem with the old “yearly release w/ lifetime per-version” licensing is that it didn’t encourage refactoring, under-the-hood improvements, etc and encouraged needless churn with UI, etc as “progress for the sake of progress” to make it more appealing to upgrade on a yearly basis.

Correction: You get perpetual access to the oldest version released during your 1 year subscription period.

My JB subscriptions expire at the end of this month, if I don't re-up, I have to downgrade to 2020.1 versions and forego all the improvements and bugfixes in 2020.2 and 2020.3 (2020.3 is the latest release, which I'm currently using).