People have been saying linux 'just works' for over a decade.

This simply isn't true for the average user.

I mean, most installs start by asking you to burn an ISO to a USB. How do I format a usb stick? What's NTFS? My USB stick is full, how do I empty it? Where do I put the thousands of pictures of my cat? Then you're not unlikely to need to change settings in your bios, some versions don't support secure boot. What's a BIOS? How do I enter the bios? Do I need to open the computer? Is there a secret button or an app for that? Sometimes you get error codes. They don't know how to google a fix. Then users have to relearn all the windows apps they're used to. Then users have to install the linux equivalent of the apps they're used to, and start learning all the differences. Then someone sends them a file in a proprietary office format and the formatting's off. They'll google excel, download the windows 'app', and become frustrated when it won't install properly.

We're talking about average users. Not people who've built their own pc. Average users are people who increasingly have trouble using a mouse, don't get how directory structures work, and mainly use apps on their phone.

It's a bit like car guys going on about how easy it is to change your own oil, to someone who's never changed a tyre and doesn't even know how to refill their windscreen washer fluid.