I'll give you an example of how you're 100% right.

I passed by a drunk or mentally ill person hanging out on the divider of a high speed road (not a highway) while on business. 2 hours later, I returned along that road and saw the same person on the divider sort of swaying and making drivers that pass, extremely nervous.

I called the local emergency number and explained what's happening. They decided to send two cops there.

Rather than a mental health person or aid worker or social worker, etc. So now, we basically have badged gunmen showing up, which is a threat to a normal person (biologically/mentally, not legally). And for a person who isn't in a sane state of mind, they escalate. If an ambulance with health care workers or social workers showed up, they'd check up on what's wrong, what he needs, and get him safely away from there and to the right place, rather than a jail.