I would say it has a way to go. Detroit 911 emergency system comes long way from pop-can-rigged fax machine | MLive.com
While under bankruptcy in 2014, a Detroit fire station rigged an emergency alert system using a pop can and a fax machine. It made national news.
Dispatchers would fax details of an emergency to the firehouse. As the fax printed out, a strategically placed pop can would be knocked to the floor, make noise and alert nearby firefighters.
Somewhat functional if completely insane. And that came with a 30 minute response time for high priority police calls and nearly that long for EMS.
Today things are better. 12 minute response time for police and 8 minutes for EMS. Those are averages. A lot of bad things can happen in 12 minutes, and you can die in 8 minutes if the circumstances are bad.
Detroit is a VERY large city. Geographically one of the largest in the US. (It may be the largest, but I won’t commit to that.) I think they did a lot of annexing in their heyday. Today with population (and taxes) down, all that real estate makes it hard to get cops and medics anywhere in a hurry. Still it is better than 30 minutes.
Calling 911 is a fine thing to do, but even if you can call 911 before bad things happen you are going to wait for a while. Maybe you will wait for a very long while.</p.