“The men I have encountered over the years can barely be bothered to wear a condom for actual sex, so I find it very difficult to believe that they’re used routinely for wanks”
They’re two pretty different things. Guys don’t like wearing condoms for sex because it means they can’t feel the inside of the vag, its lubrication, unique texture etc.
Whereas all they feel during a wank is their own hand - not wet; just regular skin. They can adjust pressure at will (can’t do that during sex unless their partner is better at kegels than I’ll ever be). So wearing a condolence during a wank doesn’t reduce sensation the way it can during sex.
Guys definitely do it. Not most, but some.