How to stop NPCs from spawning

There are possibly HUNDREDS of people that don't like this about the Sims 4 - I included - automatically generated NPC sims. This is a game where you can create your OWN people, and sometimes sims you didn't create are annoying and sometimes slow down the game when they spawn. There should be an option thst allows you to STOP NPCs from generating. I only want the sims that I create. I have deleted the households that aren't from the worlds, but every time I play a household, they come back. PLEASE make a "Stop Generating Sims" button!!!