Interesting ramble of a thread.
As a kind of aside, relevant though, cotton does not grow here, linen does. Linen does very well in the cool, moist climate and fertile lands of Northern Europe.
Our climate is Atlantic island, and is predominately damp. Cotton is damned uncomfortable stuff damp......think wet jeans
while linen, with it's long staple fibres is actually very comfortable under wool, even when the body wearing it is sweaty.
Our concept of the cotton/ linen debate is very biased, linen lost out in the mechanisation of the spinning and weaving at the start of the Industrial Revolution. It did catch up but not quickly enough. Slave labour ensured that cotton became the cheaper fabric.
Actually, as much hemp was used for clothing in the past, as ever there was linen......and the bias because some varieties yielded high cannabinoids in their leaves kind of destroyed that industry.
As for dyeing, I dye using natural dyes all the time. Linen is as easy as cotton, so that's not a good reason.
Cotton is a pain to spin by hand ( I do that too) compared to linen or hemp.
Fine spun and woven linen softens and the*handle* of the fabric improves and drapes beautifully with wear and use. Too many folks still think of linen only as starched tablecloths
Cotton will flare with fire; linen cloth, while it will burn, does not flare.
No reason 'some' cotton ought not be represented in the Living History interpretation of the past, but linen or hemp is I think a much more realistic cloth for British re-enactors to use.
Fine woollen cloth with a fine raised nap used to be called cotton, more recently it was named flannel....strangely the name we now give to cotton cloth with a raised nap....might be stretching a point there
Polycotton, while not mentioned is very available and if cotton becomes more commonly used then it will inevitably become more prevalent.
Unfortunately, if polycotton catches fire the cotton will burn to ash but the polyester will melt and forms a kind of framework that sustains the flames along the cloth. Very bad news near fires or live firing.