Bill Tuthill wrote:

but the main reason manufacturers stopped making polypro
is that it lasts so long that they can't sell replacement garments.

Polypro lasts long (I still have some that is usable and was purchased in the
'70s) but it can't hold an antibacterial treatment. Hence the smell associated
with polypro. That is a major reason for the popularity of polyester fabrics
over polypro. You're right about comfort - polyester is not not as rough and
scratchy as polypro as a base layer.