The quality of the camera and ease of setup aside (both are both fine but not exceptional, 1080p in 2022 for this kind of money is incredibly average)
There doesn't appear to be any way to receive an audible alert should your security camera see activity.
I bought both a camera and doorbell thinking these would add a layer of security to my home, so should someone attempt to break in, I would be alerted and could call the police or scare away any intruders.
Unfortunately nest/google offers only 2 types of Alert/Alarm/Notification
1 - the potential intruder rings your doorbell before trying to break in. you'll get a nice house-wide ("an unknown person is at your front door") alert
2- you get a standard indistinguishable push notification on your phone (could be an intruder, could be spam email)
There is NO option to have your nest devices, mini hub, whatever, play an alarm or alert you that someone is in your garden at 2am, but if you pay for nest aware, you can wake up later and watch them make off with your TV in 1080p.
This for me, is a KEY point of a security system, if you're not ALARMING or alerting anyone that something is breaking the security, then you cannot advertise it as a security device. It is, at best, a webcam.