I don't think there is a universal answer to this...as while I get the less stooping since it's elevated, this also raises the cabinetry if one if doing a full ~room~.

Case in point. When we did out kitchen, I went with the biggest deepest sink out there. Works fine for the wife....I hate have to bend down when scrubbing produce and such in the sink.

IMO 18” is too much and there are lots of WD with the base with a drawer to raise it so not sure what your issue is. As for the stacking ones the dryer is just reacable for most people so raising them would be kind fo useless