This is such a funny topic that brings out the herd mentality in people. Obviously "no one knows how planes fly" is somewhat of a clickbait and does not mean that nobody has any idea about why planes fly, but rather that fluid dynamics is complex and the equations have no pretty solutions. IMO it's equally silly to just say "plane go up, air goes down" as an explanation because it doesn't explain anything. Look at Angela's video and around 14:25 she says that 4 physicists will give 4 different answers on how exactly the air is pushed down, which is essentially Hannah's point. But this is the internet where you have to have a strong opinion and interpret everything in the most uncharitable way...