Android security against theft

[actionresult]

So Android 7.1.2 I have on my Nexus 6P is very secure, right? Why then if someone steals my phone they can pull down the notification shade on a LOCKED phone and switch it to airplane mode? All "find my phone" services will go bye-bye then.

 

[TwitchyPuppy]

Find My Phone also goes bye-bye if they shut down the phone or remove the SIM card (if not connected to a WiFi network).

Yet the OS is still secure

 

[actionresult]

I'm talking about software specifically, if you haven't noticed