It’s a shame for Apple that in 2023 you are not able to make apple watch give alarm sound when iphone is left behind. My Ford car which is 2011 make is able to do it, the car sounds when the key is left behind.
Apple watch is a complete waste without this feature for many of us.
You are running 5 years late in technology.
The Apple Watch can tell you when you have left your iPhone behind.
My experience is that you have to be about a 1/4 mile (0.4KM) away from the iPhone before the alert occurs. My Wife gets alerts all the time when we go for a walk, and she intentionally leaves her iPhone at home. We get to a specific place on the walk, which is about a 1/4 mile from the house, and she gets an alert.
I've driven away, and had to go back home, because I forgot my iPhone, and it happens about the same place as my Wife gets here alerts during our walks.
Apple watch not alarm when disconnected with phone
