I was curious too, so I looked into their Github issues. Apparently, SQLite doesn’t play well with k8s due to the distributed/networked nature of the environment. According to comments in the pull request, that seems to be the main driver. And apparently, Radarr already has a Postgres option.
Though, there are requests going back to 2017 to support it…just because, I guess? That person seems to just want all their data in one DB for some reason.
Good for you. My oldest backlog task is from 2012. And that was imported from the previous ticketing system (AKA an Excel Sheet).