[incongruity]

No, not at all.

Simply put, you are moving from 2 independent operations to 2 mutually exclusive operations – meaning that 1 sink (in the Dyson case) can only service 1 user at a time vs 1 sink+1 dryer/towel dispenser which can, at a minimum, service 2 users at once (there's actually a much bigger set of time/path calculations that could go in to this, but the simple case is enough to make it clear that your thinking is confused on this.)