Definitely wrong, although I do not have a collegiate off-hand understanding of biology to really fully decribe it.

Well, from reading this its pretty clear to me now that you don't know much about biology. And yet you have really strong opinions on something you have no education in.

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.

What are you even trying to say here?

Cell membranes don’t use simple diffusion to transport chemicals across.

They do for quite a lot things actually. Simple diffusion, facilitated diffusion, and active transport all take place and are all necessary for the cell to function. The ratio of cytoplasm volume to cell membrane area is relevant regardless.

By the way, you didn't need to write an entire paragraph about homeostasis or try to define what a cell is.

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.

Your perspective really comes across like you're high on something. You also apparently didn't understand what my comment was even about. It was about this sentence:

You are assuming a red blood cell is a common size

I wasn't assuming anything. In saying "correct me if I'm wrong" I was being charitable in leaving the door open that you might know something relevant about cellular scale that I didn't. But I'm pretty confident now that is not the case.