One other thought: It’s been a while since I’ve tested it, but Alexa will recognize a button press from Battery Video Doorbell, so that’s another way to add a “chime” via routine if your son is already using Echos and wants more than the Wi-Fi Chimes you’re not currently using. If he’s a Wyze subscriber, he can also enable person and package detection voice announcements on Echos for Battery Video Doorbell, and I think that’s one area where Amazon Alexa beats Google Home.
Analysis appreciated! 