From looking at history this seems confined to one generation - in 1950 the “ideal family” was a man going to work 9-5, and the women staying home to cook/clean. For a while it even worked out that way for a lot of people, but over the 1960s there was a culture revolution and women started working, while men learned to help. This process is continuing on.

Look longer over history though you see that in almost all cultures men would regularly get into situations where there were no women around to cook. Hunting, or working in the field all day often meant men and women were separated and so men had to cook for themselves if they were to eat. (women between 15 and 40 were regularly pregnant or nursing a baby - men cannot do these things, and they limit what a woman can do so some activities become men’s work.) Not to mention war which typically was mostly men, though “camp followers” did cook for the army in some cases.

Which is to say, maybe your Grandpa didn’t cook. However that men in his generation didn’t cook was an outlier. Over history men and women both cooked.