So true that the level of support varies from area to area. There are brevets where the RBA has you fill out the card, log in, sign the waiver and basically they meet you at the end and at the other extreme, volunteers with water and/or snacks at every control or with breakfast at the start and dinner at the end. I guess that is what the riders want in those areas.
I'm doing a 300k on Saturday on a route I know well, it is really nice to know a few of the controls will have volunteers with water. I know there is always the secret control at the top of the mountain (with water). On a really hot day, there is often someone (usually of the Docs) strategically located on a long waterless stretch with bottles of water. Clearly, RBAs put an enormous amount of thought into the well being of riders. Maybe I over react to bad gravel at night but I also got really messed up hitting a bunch of gravel and branches on a routing local training ride (on the road no less) after a historic storm. Lesson for me? Ride the trainer until you know the roads are cleaned up (it was almost a week after but some roads are still ruined nearly a year later) and simply avoid gravel on a road bike