> Mind you, that's if we are only considering a 2-D sphere, but space isn't 2-D you can space your orbits between 550 and 650 miles, with each 1 mile vertical increment acting as a "floor" or passing lane. You can now multiply your 265 million sq miles by 100x.

Yes but don't forget that orbits decline and only satellites with onboard propulsion have the ability to boost them back up. Everything else like cubesats and random debris doesn't and thus doesn't "stay in their lane".