Average Joe or Jill? They use an iPad.
Some do, but by no means all.
Many get by with just a smartphone.
And some, like me at present, use a MacBook Air, which is fine and dandy during an itinerant phase of my life. However, I am no fan of mobile devices, which tend to have a relatively short useful lifespan. I far prefer to use a desktop computer, with a decent sized monitor and peripherals of my choice. I am surely far from alone in that respect.
I know folks who have more than one cheap'n'cheerful older model Mac Mini set up for a variety of purposes.
Then there are the folks who realise that, to get the best out of iPads and iPhones, and even MacBooks to some extent, it is best to have a desktop base in their tech-ecosystem.
When the Mac Mini arrived on the scene in 2005 it was a fit for my needs.... I wanted a desktop that was easily transportable from time to time, but even back then when my eyesight was better than it is now, I didn't want a portable device to tote day to day. To this day I seldom even carry a mobile phone. A couple of years ago, when I came to need something more portable for work I bought the MacBook Air, but I saw it as supplementary, not my mainstay.
Beloved by pros, pundits and dilettantes when it was released, the 2018 Mac Mini was over priced and over powered with insufficient onboard storage to suit Joe or Jill Consumer, so it soon disappeared from retail displays. The 2020 update went some way to rectify the situation, but it remains a niche machine that those in the know order on-line.
As has happened with much of the Mac line up, it almost certainly needs a rethink, rejig and relaunch to ensure enough demand to keep new Mac Minis coming.