I think the parent was implicitly referring to smartphone platforms. Certainly Linux is both the most open and most private option for general computing, which is probably why the parent was lamenting the fact that privacy and openness (in smartphones) are not tightly coupled.

Sure, but on any decent phone, the only Linux you're going to get is Android.

What's wrong with openness of Android flavour of Linux, called AOSP? Yes, the hardware drivers are mostly binary blobs, but there are many binary blob drivers for PC and other hardware on Linux.

puri.sm Librem5 .. almost there.

Android itself is "open", but if you want to do much with it, you want it with Google Apps.

If by 'to do much with it' you mean asking the weather by voice, then yes. Otherwise, F-Droid provides open-source alternatives for many apps, and then many apps from Google Play Market actually work fine without Google Play Services.