once you stop paying adobe, you can't even open your files it seems!
It's not that they lock your file or anything. Once you stop paying, your software will no longer work, just the software not the file. For example, if you work in PS and save your file as TIFF and cancel the subscription, you can use other program to open your TIFF file. So you can convert all your PSD files to TIFF before cancelling. That's why Adobe doesn't have to make any "READER" program. What's the point of making PSD reader when you can view it but cannot edit anything. Then may as well convert them to TIFF, save the trouble. Also TIFF can store layers too.