Big name studios are usually publicly owned which means they have shareholders to answer to and they demand a return on their investment. That means no risk taking which means no niche genres. It’s why shareholders (ultra wealthy people) are the enemy of art and why publicly traded studios all go to shit after enough time.

And indie devs don’t want to touch the sim genre because it’s an incredibly challenging thing to make and would take most people years and years to get anywhere on it. Their only shot is having an angel investor to keep them afloat.