It was a release PS3. It was louder at launch than the PS4 at launch, but the PS3 stayed consistent, whereas the PS4 got far louder over a year or two.
I suppose size and weight factors into it, but I'm mostly just thinking about cost. Even if a screen and battery only cost tens of dollars, it's a cost that needn't be eaten by people that just want a home console.
In the interest of describing what I imagine: put the Switch dock on its side, and fatten it with an HDD and BR drive. The PS5 "brain" slots in to function like a traditional console.
Then, there's a portable dock, sold separately. It contains a screen, battery, and whatever else could be contained outside of the PS5 "brain." Again, you slot that brain in.
This would open up the market for 3rd party accessory manufacturers, who could release different form factors of the portable dock, potentially with better screens, speakers etc.
I like the cart idea that I read a few posts ago. Make it a physically large cart, and allow for huge capacity. Considering there are 400GB MicroSD cards, something like two standard SD cards stuck face to face should allow for decent capacity at a decent price.
But, that risks the PSVita memory card issue...