I intend to support SQLite for 33 more years. I take that commitment seriously and plan accordingly.

But even if my plans do not work out, the SQLite file format is fully documented and relatively simple. See https://www.sqlite.org/fileformat2.html for details. Writing a script to convert an SQLite database into a series of CSV files shouldn't take a competent hacker more than a few of hours and a novice more than a few days.

Reasonable estimates are that there are more copies of SQLite in use today than any library other than zLib. I dare say that SQLite will live as long or longer than gzip, and should both disappear, I suspect you will have a much easier time recovering content from an SQLite database than you would from a gzip file.