This is my theory
So save the world is the real world and the zombies are real people but their minds were put into the simulation
Then there was 7 universes in the simulation which each had a different version of the visitor and we know of them as the 7.
They became aware of the simulation and worked on breaking it starting with the rocket event
But this was not strong enough as in season 6 we were only able to access the “in between”
Finally the 7’s plan worked destroying the zero point/ nexus / cube, but instead of getting out of the simulation agent john Jones stopped their plan resetting the loop but in a different timeline where we meet Midas.
He lurked in the shadows remembering few things every time the loop reset
Finally there was the doomsday event where Midas found a way to break the loop by pushing back the storm.
This resulted in us being teleport-ed out of the simulation for split seconds being able to hear real words.
But then Midas’s plan backfired when John Jones team found a way to stop his plans resetting the loop once again making everyone forget about the simulation.
And that is my theory