Plus, there are pedestrians, cyclists, motorcyclists, etc., who can crash.
Was it common before to get in a serious accident but nobody calls 911?
If a call goes through when there was a legitimate accident, do the 911 operators even care, or do they assume all these automated calls are false positives?
I think it's likely that this feature does more harm than good by ddosing the 911 infrastructure.
You also don't have to search too hard to see that it has, in fact, been useful. First news search I found: https://9to5mac.com/2022/04/15/police-officer-apple-watch-fa... I see no reason to think there aren't others.
I don't have a confident answer for this at all, I think it's almost entirely subjective. There are folks who would confidently say that ANY amount of mass inconvenience is worth saving one life. There are others that would confidently say the opposite. Much more thoughtful people than I have spent a long time debating the topic on LessWrong, it's a pretty rich area of discussion.
First, there are the direct costs. If false auto-calls are clogging up 911 resources, then the taxpayers need to pay for more operators and infrastructure. This money could be used to "save lives" elsewhere.
Then there are second order effects such as lowering the signal/noise ratio of 911 calls. If operators get used to ignoring the automated calls, then the feature becomes a pure cost on society with little/no benefit.
My wife went out and bought a watch the next day.
Most crashes have at least one car involved.