I think what OP is getting at is most of us live in a tennis skill bubble. Some of us may be the king of their local club or public park and think we are hot stuff. These people have yet to be humbled by someone who trains to be more than a rec player.
Around the 4.5 mark... most players have pretty developed technique and have probably hit with high caliber players before and know what it feels like to get run ragged across the court.. basically becoming a puppet for the high level player. Most 4.0 and below would not be able to return many shots from a D1 or higher player.. whereas a 4.5 would be able to sustain a rally but would be out of his comfort zone on most shots. The OP post was kinda blatant.. but there is some truth to it in regard to people who are below a certain level have some cockiness in them because they've never experienced a high caliber player on the other side of the net, this is a run-on sentence.
"Has tennis really been far even as decided to use even go want to do look more like?" - Roger Federer (2089 U.S. Open Trophy Ceremony)