With rare exceptions (travel, training, etc.) I only shoot at the two ranges where I'm a RSO.
One of those is a members-only rifle and pistol range, locked gate, always two RSO's on duty and they stay on the line and keep an eye on things.
The other is a 25-yard pistol range, open to the public but only open for four hours per week and again with a RSO on duty and in practice 90% of the shooters are regulars. At this one there's the added feature since it's a relatively small line with only 10 slots that the RSO pulls a barrier across at every break... so it's really obvious if anyone even thinks about going too close to the line.
What may be less obvious at both places is that there are pretty much always other RSOs present either to shoot or just to be voluntary backup even when it's not their duty day. Not unusual for there to be half a dozen of us present. There's a fair amount of unspoken communication: The lead RSO has to devote some attention to a shooter having a technical glitch, and someone else steps behind the line to watch until thats all sorted out. Most of the shooters never notice, they think someone is just taking a break. Occasionally it gets more formal. Once the duty RSO pointed out to two of us a slightly sketchy guy he wanted to keep a close eye on, and we'd both already seen him and both stepped back to have a clear line of sight. In that case the guy turned out to be OK, just inexperienced and nervous, but better to be safe.
There are a couple of other places in the region where I absolutely will not shoot or even visit, not ever. Too many shooters, most inexperienced, little or no supervision, poor sight lines.