Yeah, the gym is full of rocket scientists.
Maybe the average gym goers, but the people that do it for competition and as athletes in other sports know their stuff. I learned a lot during my time as an amateur body-builder and it has carried forward. I am mid 60’s 6’2” and weigh 225-235 in off season and cut down to 190-200 for competitions with 7-10% body fat depending on season. I only take protein powder shakes, pre-workout, BBCA replacements, and creatine and it has worked well for me. Other than a yearly physical I haven’t been to the doctor since late 50’s age when I started BB. Didn’t get COVID nor the flu either.