You guessed wrong. Multiple data centres are as much about redundancy and resiliency, and latency.
As for the cost, data centre space, business grade communication lines, and staff are orders of magnitude more expensive than the physical hardware they support.
I'd like to call you out on your continuing reduction to absurdity and slippery slope arguments. Just because we can't handle 4GB blocks today, doesn't mean we shouldn't aim in that direction. Doesn't mean we shouldn't be taking our first second and third baby steps in that direction.
If the obsession with every personal computer being able to run a fill node continues then bitcoin will be consigned to the dustbin of history, a footnote to the story of the global crypto currency that eventually took over the world.
Thanks
Rodney