It's fine to muck around doing 120kg squats if that's your thing, but you're continuously putting yourself to increased risk of injury as the years go by and you're increasing weight. To mitigate that risk you then have to start doing additional warm up, foam rolls, recovery routines. Oh and lets not forget that most people can't even do squat properly, so add static stretching too. That's hell of a commitment to someone who likely hates the process and just wants to be healthy.
That said, I also do weight training, but I don't emphasize it due to above. 2x/week full-body base, 2x/week 30 min cardio, 2x week static stretches. Am I advanced in anything? No. Am I rounded more than person going to the gym 3 times a week? I'd think so.