As for the 486, I brought it down to my dads when I moved, and switched to using his much more modern system. It did eventually "die" in 2007-2008. My dad threw it out after the clock chip failed on the motherboard. I was pretty bummed because it sounds like a fairly straightforward fix / such a minor issue, but he's as sentimental as I and referred to it as "an old clunker".
They don't build em like they used to! The Pentium 1 interior blew me away upon opening it. Not a tad of corrision, rust, or even dust! Also the disks are still in top notch shape and seem to read just fine.
At least you have your Pentium. I've still got a bunch of my old code from the 90s and I'd have a very hard time getting any of it to run on a modern PC.
He has been lucky that his 486 don't broke, but sometimes the old hardware is more resilient what you think. The only hard drives that I seen to die, was modern hard drives of >100GiB . However, I have here an Amiga 1200 with a little hard disk of 200MiB that it keeps working fine.
The terms used in the article are misleading though, like many people have already pointed out. Not an OS, a shell, I don't even know if you can build an OS with QBASIC alone, maybe with some assembler support, but I don't recall qbasic supporting assembler, at least without any binary tricks ?