Betz limit and power available in the wind

Assuming the weight of a parachute could be 0.1 kg/m², the total weight would be 6 tons. This would be approximately the mass of a 4 MW rigid glider with a high L/D ratio, which would have a very high cut-in wind speed requiring frequent landings and takeoffs, if of course it completed flights without too much risks of crashes.

A parachute has a much lower wing loading per unit area, which allows it to stay aloft even in light winds.

This would reduce the total surface area (for 4 MW) from 60,000 m² to 20,000 m², which would start to be acceptable with a train of many stacked units going high enough to exploit the truly high altitude winds. And very high coefficients (Cd) of 2.2 and more were reported, as well as a very High drag coefficient (Cd) of 2.727 for a parasail, and lift force (as for any parasails), tested and reported on
Sea recovery system for small UAV | NTU Singapore.

Zhonglu High Altitude Wind Power System began flying trains of parachutes while generating some power (22 kW?).