Most of the lands in my last game were bronze-age. The Dwarves had access to Iron and Steel, though.
Why bother? Iron helps against the fae, of course, but I also introduced Tetanus. Aka every iron / steel weapon had a chance of inflicting a disease.
(I know, rust doesn’t cause tetanus, but it aids the bacteria and was considered to be the source for a while. I have ‘miasma’ in my games too.)