The bigger issue would be ISA control cards and the like. A HN user recently posted a link of "new" ISA boards for sale, but the latest CPU support was Pentium 4 (about 20 years ago).
No, you can find plenty of ones that will hold a recent i7:
https://www.dfi.com/product/index/1502
https://ipc.msi.com/product_detail/Industrial-Motherboard/AT...
http://ibase-usa.com/english/ProductDetail/EmbeddedComputing...
(I wish they would make "ultimate" mobos with all the interfaces in between too --- I mean if ISA with a Coffee Lake CPU is possible, how about a pair of IDEs, floppies, and parallel ports too...)
._.
Even if you assume it can boot DOS, it doesn't mean it can run DOS. No DOS has drivers for a lot of modern hardware, and they're never going to be written.
> (If not, sounds like a bug.)
BIOS is buggy? Say it ain't so! Say! It! Ain't! So!
Additionally, over the last several years, I've used it on probably a dozen or more different "makes and models" of enterprise server hardware to update firmware (BIOS/HBA/NIC/SSD) and can't recall experiencing any major issues while doing so (fortunately, more and more of these bootable firmware update utilities are now Linux-based!).
That's with FreeDOS 1.0, by the way. A quick check shows that it was released in 2006, making it a fair bit older than the servers I most recently used it on. For what it's worth, FreeDOS 1.2 was released four years ago and the third release candidate of 1.3 was just released this past summer. It seems that FreeDOS, at 26, is still alive and, in fact, doing quite well!
To be clear, I've not actually attempted to boot any of the other DOS systems in, well, quite a long time -- at least 10 years for MS-DOS and likely 20 years or more for DR-DOS and PC-DOS -- as I haven't had any reason to. FreeDOS has been a superior replacement since before the turn of the century.
In my case, FreeDOS is booted via (i)PXE and the "hard disk" (image), which contains the various firmware images, utilities, etc., is downloaded via HTTP and loaded as a ramdisk. In those rare instances when it's actually been needed, it is just so absolutely useful.
Honestly, I'd be a bit surprised if MS-DOS (a.k.a. PC-DOS) did not (for the most part) also "just work"(TM) ...
... and, now that I've said that, I'm fairly confident that MS-DOS 5.0 (1991, IIRC?) is also available on the netboot server. I can't confirm that at the moment but (assuming it is) now I'm quite curious so I'll try to remember to try booting my workstation into it the next time I happen to restart it.
Of course, if New York's subway controls are anything to go by, 2107 is pretty reasonable.
I wouldn't be surprised at all if there were some original embedded systems still running machinery and the like in a century from now, catastrophic events notwithstanding. The sort of low-power embedded systems likely to be running DOS don't really experience any wear. There's quite a bit of equipment in the "low-level" manufacturing industry which is around a century old, and has basically been in continuous operation since it was installed.