I love my Mint laptop and I find it plausible that someone who just does “the basics” could get by with a usability-focused distro.

In my experience, the problem is that not a lot of people really are just sticking to basics on their PC anymore. The truly “just browsing and email” users just use their phone. Someone with a PC is doing something—gaming, photo editing/digital art, audio production, long form writing—where they have a proprietary app they like. Either that, or they’re using it for work and have a company controlled, fully Office 365’d PC.

Linux got usable enough for basic users, but basic users left PCs behind.