Not trusting the software at all is the only real solution. The only operating system that makes that practical is Qubes OS. One can always manage a lot of VM'

Not trusting the software at all is the only real solution. The only operating system that makes that practical is Qubes OS. One can always manage a lot of VM's manually, but that's complicated enough that one usually only bothers for very specific software, and not everything like what is done in Qubes OS.