Don't listen to the incels This movie was good. not great, but still had its moments. Sure, the science is a bit lacking (when the balloon hits an air pocket at starts falling, it doesn't magically just stop like it hit the ground), but the script is still well written and the cinematography quite good.
It's based off two different real people that had nothing to do with each others. The incels are mad that a woman (gasp!) took the place of a man. But the woman was an actual aeronaut; Coxwell was replaced by well-known aeronaut Sophie Blanchard.
This, like almost every other "based-off" movie, is just a lose representation. It's still a good movie and never meant to be historically accurate.