even if they get "free multithreading" with no-GIL, their system eventually will overgrow one beefy machine and will need to be deployed across a fleet of 10/100/1000 machines.
at which point you lose benefit of no-GIL, because you now have to introduce redis and kafka into the system
at which point you lose benefit of no-GIL, because you now have to introduce redis and kafka into the system