The 80286 CPUs did support up to 16 MB of RAM, but they needed to be switched into protected mode to be able to use it. The problem was, that there was no way to switch back, except reset. That might be the reason, why MS DOS never supported this mode.
With 80386, it was possible to run in protected mode AND run real mode binaries in VM86 mode, which is exactly what Windows 3.x used.
The 80286 reset thing wasn't a full PC reset, but a CPU reset.
True
> The 80286 reset thing wasn't a full PC reset, but a CPU reset.
That required an extra hardware and BIOS support. The CPU had to be reset externally, and after jumping to FFFF:0000, the BIOS had to recognize that this is a CPU reset, not re-initialize the hardware and return execution to where it came from.
That excuse is valid for 8086, but it's no longer valid for the 386.
Even when expanded memory was an option, loading a bank switching memory extender to work around the cpu’s Address range limitations left less base memory left for non-EMM aware apps to run in. Many times I remember discussing with users the pros and cons of different memory managers and aporoaches, but most of the time in that era, not using them at all and using bare bones MS-DOS was actually the best choice. Some users would have two boot disks. One without EMM386 to run software that wasn’t expanded/extended memory aware to maximise the memory available to them, and another with EMM386 to run one or two apps that were.
The hardware supported more than 1MB, as later CPUs proved. However, MS-DOS didn't really support it, as EMS/XMS proved:
https://www.filfre.net/2017/04/the-640-k-barrier/
I'd say that you've got it backwards, in my opinion. And in the opinion of that fine article I linked.