Perhaps the answers are: 1. 1st-party OS installations in which the OS creators sell you the hardware with only the OS installed (Apple). Or possibly 3rd parti

Perhaps the answers are: 1. 1st-party OS installations in which the OS creators sell you the hardware with only the OS installed (Apple). Or possibly 3rd parties can license your OS only if they don't install any additional software (sort of like Nexus phones). Or obviously you could install Linux distros yourself... which is not appealing to most people. 2. Monitored software installations either in the form of (A) community managed software repositories as done with Linux distros and the BSDs, and/or (B) "app stores" with restrictive policies and sandboxed apps.