Conventional rail has hit 575km/h in tests (https://en.wikipedia.org/wiki/TGV_world_speed_record https://en.wikipedia.org/wiki/TGV_world_speed_record). What adv

Conventional rail has hit 575km/h in tests (https://en.wikipedia.org/wiki/TGV_world_speed_record https://en.wikipedia.org/wiki/TGV_world_speed_record). What advantage does Maglev give? It mainly seems super expensive and incompatible with existing networks. Note the main way in which the JR Maglev will allow adding speed is by building a very straight line for a lot of money, which could benefit conventional rail just as well.