I was a public safety dispatcher in the late 70's, as cb was starting to wind down. We had a cb in the dispatch center and monitored 9. Even then, I can count on 1 hand the number of calls I had on the cb for help. I think it is highly unlikely today anyone would use a cb to call for help, and even more unlikely to find it.
It's a statistical thing. What is the probability of receiving a call for help on cb9 when there are so few cb operators to begin with, and probably all of them are equipped with a cell phone? The low "base rate" of operators, also creates an even lower number of channel 9 monitors. Therefore, the probability of someone having an emergency, using cb9 to call for help, and having it received is very very small.
BUT, I hope if someone does, they are within a couple miles of you!
Like you, perhaps. I am more interested in ham or GMRS now, which are not served by anything like an "emergency" channel. However, one reason I use ham radio is to have the potential of reaching help by radio if I am somewhere the cell phones do not reach, like in a national park. You have to do the research to know what bands and freqs are active or monitored.
I guess truck drivers will always use the old "Class D" citizen's radio service, but I think it has long outlived any general public interest, IMHO