Can someone explain — in layman's terms — what Tuta's newly announced "quantum-resistant" feature means and how is it relevant to the average user?

And how much, if at all, ["quantum-resistant email service"](https://www.techradar.com/computing/computing-security/tuta-becomes-the-first-quantum-resistant-email-service-with-new-hybrid-protocol) elevates Tuta's security above any of its competitors?

It is free to all new accounts so it is rare to see one of the advanced security features not being relegated to paid tiers of service; in the same sense, the nature of it being free also makes me skeptical on some level that it is that much of an advantage versus what they currently offer and/or versus what competitors' offer.

accounts advanced features free nature offer paid privacy security security features service