There are two situations where it pings: 1) After a set amount of time (around 5 minutes or so). This is to ensure you are awake. 2) If it hits a turn or situation where it is less confident. 3) Major escalation in situations where a crash may be imminent (this ping is much louder and urgent).

Agree that on straightaways, the pings are pretty infrequent.

You can use Autopilot for five minutes without your hands on the wheel, and it won't even beep at you?

The "killer app" everyone is expecting is: get in, tap destination, and peruse media for the duration.

That will require a stage of using Autopilot for five minutes without your hands on the wheel, and it won't even beep at you.

Sure, but the unstated assumption there is that stage won't also force-feed you the side of a tractor trailer through your windshield.

Currently Tesla's cars act as though they've satisfied that assumption even though they haven't, and someone died over it. Tesla absolutely should not be acting like they've created a self-driving car with safety features that let you ignore the road when in fact they are driving assists and you still have to maintain awareness.

There are multiple paths to that destination, Google is taking one without the pit stop at 5 minutes.

It should give a visual and loud acoustic alarm after 5 seconds of taking your hands of the wheel or losing confidence.

The driver is compelled to keep their hands on the wheel by the relevant laws/regulations, not by the car, same as every other car manufactured in the last 100 years.