Technology

Making it affordable would completely destroy European flights, which is a good thing.

that's the problem unfortunately. maglevs use superconductors, which have to be cooled to an insane degree (i.e. using liquid helium or liquid nitrogen in the best case) that suck up so much energy that we wont be able to use them on mass scale until we like crack fusion or something, or alternatively find a room temp atmospheric pressure super conductor.