Ryanair takes about 30 minutes to turn a plane around with say 170 seats. It's also a large object that requires spacing to get in and out of the gate.

There's no real way I can see to improve airport design with those constraints.

You can fit maybe 4 platforms each holding 10 car trains in the space of one gate at a train station.

A380s require even more space and take even longer to deplane and board, so I don't think fewer but larger planes would work either.

EG: Atlanta airport does around 100m pax. So does Waterloo station in London. Look at the land take and size of terminals required in each of those cases.

What about the massive environmental impact that flying has?

You also need to get to the airport and from the airport. Airports are usually quite far from city centers.

Well, thats what light rail and cars are for. I mean, how are you getting to this proposed hyperloop station? Same way.

You could build hyperloop stations in city centers. That's why travelling by train is (often) so convenient. No need for 1h trip to/from the airport.