Don't forget the atmospheric density
Up by a factor of 4.5, so that 70 lb would only need the sort of wings that would lift 15 lb on Earth.
Of course, you'd still have to exert the 7o lb of force, but a fit person could do that for a short time.
There's also viscosity to take into account. Higher pressure leads to higher viscosity (lower temperature opposes this, for a gas)
So you're right, in a way. A man* couldn't fly for hours, but he could certainly fly for seconds or minutes, and glide all day.
The term "man" includes humans of any gender, specifically including females.