We get them every single time a thunderstorm sniffs at anything in the tricounty area.
There may be a way to turn off the "Watch" alerts and still keep the "we are gonna die" alerts. The one time we got the green sky of doom the phone did explode in a way not normally seen, so I assume they know something about crying wolf.
As for amber alerts being useless - something like 90% (?) of the time it's a custody dispute where one parent hasn't returned the kid at the appointed time.