Those reasons certainly make sense, given the less than ideal environment into which many will install their console. My media unit is (very deliberately) open

Those reasons certainly make sense, given the less than ideal environment into which many will install their console. My media unit is (very deliberately) open at the front to allow for maximum airflow, although this does make it something of a pain to dust. Still, it is possible to design components - even those that generate significant heat - to be stackable. My hi-fi amp generates quite a bit of heat but uses a massive heatsink along with vents all around the case to manage it. I do wonder, if the PS5 were simply a cuboid with a couple of larger (and quieter) fans, the kind of heavy duty heatsink it already has, plus plenty of vents around the case, whether that would work. But, as you say, it comes back to dust, and those air vents would be the perfect route for that dust to enter the device, particularly if it's sat on the carpet (which its form factor pretty much guarantees it will be in many homes).