As a counterpoint these "imperative systems" don't need hardware acceleration to be responsive. (why the hell does responsive mean "looks good on my phone" nowadays?)
Drawing everything on CPU and overdrawing/changing state like crazy (in kernel mode, even, for GDI!) is very much not responsive and not efficient. It only seems that way because (1) graphically, those apps are so simple, as the systems were designed for '90s hardware; (2) desktop CPUs are so fast that you can be really slow and still remain responsive.