> There is no privacy advantage by using MicroG compared to Google play services. You still connect to there service all the same giving privileged access to your device.
...assuming you are connected all the time, or at least that the services are running all the time. In my case they are not. I only enable them every once in a while, when I need to be alerted of something. This might not be how most people use their phones, but I do it because there is no way to preserve any privacy at all if you are running Google services 24/7 (sandboxed or not).
I see Google services as malicious software - not security malicious (Google can't risk that) but privacy malicious. This is why I care more about ability to turn them on / off than about what kind of access they have. Even inside the sandbox, as regular apps, they have way too much info about me.
As I said: I would prefer sandoxed MicroG, but given the available options non-sandboxed MicroG is preferable to sandboxed always-on Google services.