Couldn’t the Vex leave the Vault of Glass?

Does anyone know why the Vex don’t make an infinite army in the Vault of Glass and then take over everything?

The Vault of Glass is separate from the universe. That’s why when we open the door, we are syncing it to the world. It has its own timeline inside the Vault. So if they made an army, it couldn’t be an endless amount because of it’s timeline.

Also if im correct the vex don’t inherently want to take everything over they want to cement themselves as a permanent part of time and then by default end up ruling everything