Locking up is a great way to get some piece of mind. Another way is insurance! It's not too expensive compared to an expensive bike. You can also setup your own "insurance" by opening a savings account/index funds/rotating CoDs with some money and deposit a monthly value of your choice (gas money saved per month, what private insurance would be, or as a general savings goal).
IMHO, scooters are so inexpensive that it's not a huge deal to buy a new one when it's stolen. This is true for ebikes too, though it can be a little more painful. Try comparing such a loss to how much you're paying for transportation and you'll find that a bike isn't the biggest slice of that pie. Use that knowledge to relish the thought with your coffee after not paying for gas or a parking meter.
In this incident there was a passenger in the car. They were not injured.
The rolling taxis problem is still a thing though. I know there's lots for these self-driving cars to hang out in, but even that means a return trip back to base is without passengers.