I live in Phoenix which is the center of the county under Sheriff Arpiao. He is a real mixed bag in terms of his political principles. He doesn't seem to have a strong grasp of individual rights and he is constantly mired in controversy, but on the other hand he is well known for thinking out of the box when it comes to being effective in law enforcement. To avoid overcrowded in the jails, he has a tent-city set up as a jail. One his best projects, started long ago, is the volunteer Sheriff's Posse. People can volunteer, get training, and patrol in a car that can't be distinguished from the regular patrol vehicle. They have their own buildings in different parts of the city. The voluteers don't carry arms, but they patrol, and radio in for a sheriff's deputy when they spot problems. It is all privately financed - every penny - and has worked to be a great force multiplier. They do patrol, search and rescue, prisoner transport, mall patrols, etc.
When more people carry guns, there will be more accidental shootings, and more arguments that end in gunfire. But there will be less violent crime and fewer murders - the statistics already show that the net balance strongly favors lower murder rates, and far less crime overall.
The real measure of the worth of increased concealed carry is that people can protect themselves. When the social fabric is as tattered as it is today, and dangers abound, then the need for self-protection is great. If we had a society that was more benevolent and less violent, there would be less need.
Good people carrying guns is a good thing.... until such time as there is no longer a need for carrying. And when that time comes, people will put their guns away.
Open carry isn't as effective as concealed carry because it somewhat defeats the purpose of self-protection - it gives away the factor of surprise and may even attract those thugs that would want to take an openly carried weapon from them. Concealed carry is a slightly better form of self-protection.