No it's not false and it precisely answers your question. High pixel density captures less photons per pixel.
Don't patronize people who have far more experience than you. I have been a pro photographer for over 30 years. 10 of them I worked on image intensification systems 1st through 3rd generation. The issue IS in fact the amplification of the signal when there are far few photons to discern the signal from the noise. It's quite obvious that your little brain cannot grasp the concept of photons across a surface area. I suppose you have as many brain cells as fit in a singe pixel. To me you are just noise.
I am quite done with this.
That doesn't answer the question and is patently false when you use my just as valid comparison, which is why I did it.
It seems nobody knows what component or process is used in 1 series cameras than enable more severe adjustments to a RAW file than a 5 series cameras RAW file.
I believe, sir, you are the one taking a patronising tone "To me you are just noise"
indeed! Experience, how would you know what experience I have?¹ As Neuro quite rightly points out your over simplification, is so oversimplified and patently false, it is of no value, and is certainly not the answer.
But you are not reading the words I write. Compare a same density and generation, heck it is the same sensor (effectively), 1Ds MkIII and a 5D MkII RAW file (which completely nullifies your suggestion about density and amplification) and you will see the difference. My "little brain"
is interested in what, exactly, makes that difference. I am not surprised there is a difference, and I am certainly not underestimating built in obsolescence or model differentiation, but there are some members here with very in depth knowledge and interest in these things and the hope was one of them might have read and understood a white paper or patent or some such technical document that would actually answer, at least in part, the specific question.
You don't have the answer, by your reply I'd suggest you didn't even understand the question. I don't know the answer either, again as Neuro suggests, I suspect nobody here does.
Note: 1. For the record I got my first paid photography work in 1978 and shot my first wedding as primary (only) shooter in 1980. For whatever that is worth.............