As a long time user of Damn Small Linux, Slackware, SUSE, Gentoo, and Debian, I frequently test distros for security against various cybersecurity standards (starting with Common Core and CISecurity), I also implement Linux across CPU architectures for various embedded IoT:
Linux Mint is what I always put on for new family members.
Disclaimer: original investor of RedHat.
That’s a solid endorsement, especially coming from someone with your background in RedHat and the older distros. It seems we agree that for the 'non-tech' family members or those just transitioning, Mint is the bridge that actually stays standing. The stability for IoT you mentioned is a great point too—often overlooked in favor of more 'exciting' but fragile setups.