I think you two are talking past each other. You don't jump straight into 300 lb squats. You start with squatting with no barbell. Then you add an empty one. Then you add 20 lbs. Then another 20 lbs. In a few months, you have a lot of weight. This is going to get you stronger faster and safer than trying to do pistols (one legged squats) because you control the weight advancement. This is true for all weighted exercises vs body weight that I can think of. Pistols are hard and rough on your knee and the form is hard to get right. My back squat is over 2x bodyweight and is still find pistols hard and rough on my knees.

First off, you are wrong if you think that bodyweight exercises cannot injure you. Even something as simple as doing pushups with bad form for too long can have a detrimental effect on your posture and cause back issues.

Also, that's a false comparison. Nobody said that you need to get off the couch and go straight to squat 500lbs to be in shape. You need a proper training plan with reasonable progression, and you need to start as low and as light as necessary, no matter the training stimulus (BW, barbells, dumbbell, kettlebells, bands, ...). The difference is that weights can provide an external force that can be scaled to your strength in many ways that BW training cannot, because in BW training the only weight is your body and you need to use leverages to modify your training stimulus.

Finally, BW versus weights is a dumb debate. They complement each other, and a well-rounded athlete should do both.

You are right though, this is not a fight for either, I should reiterate that I think that STARTING with BW first to help your body adjust, and when you have an initial, flexible and durable base to work with, you can go crazy with whatever next goal you set. That is what I would prefer for myself I could go back in time, anyway :P

I kind of disagree and agree at the same time. I'd recommend that a new trainee start with simple bodyweight stuff* but for different reasons: it's an excellent teacher of proprioception, which is one of the things that couch-to-barbell people like myself tend to lack, and it's now starting to bite me in the ass now that my numbers have grown more respectable and that I can find myself squatting 450lbs with ease but having a hard time doing unweighted lunges.

*to be fair, I'd recommend that a new trainee start with anything but barbell stuff. Simple bodyweight training 3-4 times a week, playing a real sport once-twice a week and doing some form of cardio twice a week should be the starting point of any athletic career, at least for 3-6 years. I started training with people who had an athletic past like this and they blew past me at an incredible speed progress-wise, and ended up stronger, healthier and in better shape than I ever was.

Don't use heavy weights, use light weight and add slowly.

When I was around 16 years old and started training with weights (just like what my father recommended me doing), and gradually increased the weights, there were joints and muscle groups in my body that just could not adjust. I had no way of improving triceps reasonably alongside the rest for pushups for example, and my right shoulder had the weirdest pain points whenever I moved weights with it beyond the initial smaller scales. So I eventually gave up.

Fast forward a decade, and my right shoulder still remembers these pains - I dunno if the weights caused it or some previous injury, but when I started training with my own weight, one sign that I was getting ahead of myself was that small pain. Now I can progress slower, but still I have to be very careful. Some of the exercises with heavy weights are just not natural for the body and simply exhaust/strain it more than it should. If you are experienced, you can work around these limitations, but I prefer body-weight exercises now.

Your issue is that you were 16. I don't mean that weight training young is bad, but that you were a 16 year old training himself. People think that because lifting weight is a meathead sport you would have to be an idiot to do it wrong, but that is incorrect. Lifting weights is easy, but lifting weights in a way that makes you progress towards your goal and emphasizes longevity in the sport is hard and the domain of experienced strength coaches who have seen it all.

You were increasing the weights at a rate that your body couldn't handle. It is very frequent with new trainees because the neurological adaptations that appear at the beginning of training are always impressive: you finally learn how to use those muscles you always had and make them work towards a simple common goal, lifting that barbell. The main problem is that the rest of your body sometimes cannot keep up with that speed, and that results in this sort of issue. Had you been to a professional strength coach, he or she would have forced you to lower your pace and think about long-term progress over short term gain, which would probably have been at your 16 year old self's annoyance (as it was to mine).

Yeah, you are right, most likely. I remember quitting then due to being frustrated over lack of progress. Hah!