Unfortunately I don’t think these issues are limited to commercial gyms. In fact, I would say an intelligent high school athlete who is willing to do some research and talk to several experienced lifters might have a better chance to figure things out at the local Y than at his high school. My kids graduated from a very good school in a suburb of Dallas. Our 14000’+ facility is probably one of the best in the country for high schools. You can see it here https://schooldesigns.com/Project-Details.aspx?Project_ID=1117
If you scroll the pictures you will find one of the weight room.
However, even though we have been ranked in the top 10 nationally in the past couple of years, and two years ago lost only one game, and that by one point in the final second to Trinity, the #1 team in the nation, and this year, last I checked, ranked #17 in the nation and #4 in Texas, and we do have some exceptionally quick and a few fairly strong kids, the truth is they know very little about weight training. My son played football for CHS, graduating last year, and I routinely questioned all of his buddies about their training. They are not educated about training and the workouts they do are not designed towards mass, strength or power. The workouts described to me are simple, generic weight training anyone might do. My son was best friends with the top three or four basketball players, and I’m not sure they even knew where the gym was. I know the baseball and track athletes have no idea where the gym is, unless that is they played football. The kids are so incredibly busy, and many playing multiple sports, AAU, summer ball etc. etc., a long term weight lifting program is not on most agendas.
Bottom line, unless there is a motivated, educated, informed strength coach around who can educate and motivate the student athletes to learn how to train, its going to be pretty much hit and miss in the gym for most high schools and small colleges. At least in my experience.