How does having some kill switch solve the issue of an app that needs geolocation selling the data or otherwise using it in a way other than you intended?
Having an OS and apps I can trust to not send location data solves that problem. The kill switches ensures no roving bugs, modem AT commands, and passive tower triangulation when I'm not using the radio. Pretty simple really.
That argument is so tired. Just because there's no perfect privacy, doesn't mean you can't significantly increase it. At some point you also have to trust that the chair you're sitting on will hold you and the one that isn't visibly weak has the best chance of doing that.
Only using “app you can trust” seriously limits what you can do on your device. This might be a solution for you, but it’s really not a solution to the privacy problem, it’s duct-tape on something that needs to be fixed on a larger scale.