The files you can actually see in Poser are not the ones you move. (Though you can if you want to.)

The folder that must be in the main runtime is called !DAZ, and is in Libraries. It's not visible from within Poser. Put it in Libraries in the main runtime.

If you're only using one runtime, you don't have to worry about it.

I don't think there's a !DAZ People folder. It's called DAZ People.

What version of Poser are you using? P4/PP can't handle too many folders, or folders that are too deeply nested.