I’m sorry you’ve had a bad experience with snap remove deleting your user data. We are indeed aware that the current implementation results in data removal when snaps are removed. This is terribly unfortunate timing for you as the latest release of snapd - 2.39 - which is due out very soon - resolves this issue.
“With automatic snapshots feature landed and to be released with 2.39, snapd now creates a snapshot of the snap data and configuration automatically on snap remove and keeps it around for 31 days by default.”
Sadly this doesn’t help you with the situation you’re in. The best thing I can recommend is that you restore the specific ~/snap/superproductivity directory from your backups, and then re-install the snap. This will re-instate the system as it was when you took the system backup.