I do this outbound filtering but I don't use a computer running Windows or MacOS to do it

It doesn't make sense to expect the companies promoting Windows or MacOS to allow the user to potentially interfere with their "services" and surveillance business model

Windows and MacOS both "phone home" (unfiltered outgoing connections). If computer owners running these corporate OS were given an easy way to stop this, then it stands to reason that owners would stop the connections back to the mothership. That means loss of surveillance potential and lost revenue

As of 2006, still nothing stops anyone from setting the gateway of their computer running a corporate OS to point to a computer running a non-corporate OS that can do the outbound filtering