Most people could for sure: but in the same way that most people could do the motorcycle maintenance I do regularly.

Remove spark plugs to inspect, change the brake pads, change the oil and replace the oil filter, top up the brake fluid, heck: even just get the chain tension correct. None of it’s even physically difficult, but most people are terrified of breaking something, or otherwise so unfamiliar with the basic tools required that “torque to spec” sounds more like a spell than instruction.

The last time I installed Linux mint, something went screwy with the partition, so I had to run a couple updates in Linux and then a couple command line arguments to get it to show the grub on startup. That process was easy, but someone unfamiliar would hardly know what to search for, and would likely be as uncomfortable for many folks as it would be to get a stripped bolt out of the engine case. Not rocket surgery, but intimidating the first time, and possibly the point at which they get a professional involved.