I think my first distro was Ubuntu ( but that was because everyone around me was using it only) before I finally migrated to Debian less than a year later. Mint and Ubuntu both use Debian as their base. (Mint technically uses Ubuntu as it’s base but has a Debian edition as well for backup reasons).

I know Debian’s problem is it’s software repos(Debian Stable can be filled with older versions of software). But it can’t be denied that it is rock solid (for most part), has a comparatively decent set of software in its repos and a large set of distros use it as their base.