Yeah. Long mode is a bit of a line in the sand, leaving many features behind that were kept for compatibility (segmentation, vm86...). It came at a time where,

Yeah. Long mode is a bit of a line in the sand, leaving many features behind that were kept for compatibility (segmentation, vm86...). It came at a time where, fortunately, the mainstream OSes had enough abstraction so that software did not have to be written for what effectively was the bare metal anymore, with DOS almost being more of a "software bootloader with filesystem services".