I think it's silly to extrapolate exponential trends 400+ years into the future while assuming that humanity remains confined to Earth.
Elon Musk's goal for SpaceX is for humans to live on Mars, but Jeff Bezos's goal for Blue Origin may ultimately be more practical: to make it unnecessary for humans to move off of Earth by moving industry to space instead. With industry in space, Earth can remain a nice place for humans to live even as economic activity continues to grow for millennia. By which time we'll probably have found new Earths to colonize in other star systems.
Elon Musk's goal for SpaceX is for humans to live on Mars, but Jeff Bezos's goal for Blue Origin may ultimately be more practical: to make it unnecessary for humans to move off of Earth by moving industry to space instead. With industry in space, Earth can remain a nice place for humans to live even as economic activity continues to grow for millennia. By which time we'll probably have found new Earths to colonize in other star systems.