FTFY
or at least Windows XP
It’s more nuanced than that. Windows was built on top of DOS and architecturally and for backwards-compatibility a lot of those things stuck around. But it’s not fair to say that Windows 10 is the same under the hood as pre-Windows (3.1) DOS, when computers have evolved so much in those 25+ years.
The comparison (or lack thereof) is to Windows 10 because that’s what many people are using now, and the question is whether to upgrade.