It's a lovely, if dystopian vision. unfortunately this is all on Google.
1) Things started going pear-shaped after the March 7 update.
2) Rebooting the phone does not improve performance.
3) uninstalling Google Fi, resetting the SIM card and reinstalling Google Fi does not improve performance.
4) I can be running and streaming Google Music over T-Mobile but I can't send or receive calls if the phone thinks it's talking to xfinitywifi.
5) Attempting to force it onto Sprint causes it to brick to the point where it won't even accept dialer codes until it's been soft reset.
6) A stingray that stays in one place is called a tap. Stingrays move around and, therefore, would cause intermittent problems. I, on the other hand, have 100% repro.
7) The issue is also displayed at my wife's work four miles south in the heart of Mountlake Terrace, three full miles from 99.