Definitely wrong, although I do not have a collegiate off-hand understanding of biology to really fully decribe it.
But it comes down to what does a "cell" mean in biology? Even your case in point specifies an object with many cells in it.
Cell membranes don't use simple diffusion to transport chemicals across. That's the entire point of a "cell". It's a defined region that at least attempts to control its own various chemical balances. Cells do have many gates that allow many molecules across, unfortunately including many viruses and prions. Unfortuntely, cell walls are also not impervious to truly toxic chemicals, either, so a "cell wall" still can absolutely break down with minimal effort with the right chemicals. They do attempt to control their own balances though, including basic ionic content. That's the whole point. The attempt.
I really have to ask... Why do you think humans aren't so big on the scale of life? Your perspective really come across as human-centric. Not "bad" by itself, but still wholly incompatible with reality.
The thing that does change in relation to diffusion at scale is the necessity of circulatory and respertory systems, which is a massive order of magnitude or few increase in complexity than cells.
lol so you defend that which you do not even use and that which you do not undertand? What a joke...
My hatred is anything but blind, and you calling it such is sealioning beyond belief. I love your hypocrisy... An Apple user without even using Apple products... Truly, your lot in life is more dreary than you could ever admit.