> Say you stopped using Photoshop years ago but suddenly need to export one of your old documents. You’re now forced to pay rent to Adobe for at least one month to access one of your own files. And Adobe won’t make it easy to unsubscribe again, which adds to the hassle.

Yes, if a software uses a proprietary file format and you lose access to that software, then you can't open the files anymore. That sounds pretty straightforward to me. Though in the case of Photoshop files it doesn't really apply, as a lot of other software accepts their file format.

> Perpetual fallback licenses[1] solve that issue without forcing users to keep paying rent.

That's basically what I meant with paid updates. I know the model, I use Jetbrains software. I don't think the model would work as universally as subscriptions. I expect most people wouldn't keep paying if the maintainers are only doing stability and bug fixing work, as long as these specific issues don't affect them, which in turn would raise the price of a single fallback license.