You can build elite levels of upper body strength with gymnastics style front lever, planche, manna, etc. There are crossfit guys who have accidentally 3 plates or more on the bench by doing ring dips. If you can do full range handstand pushups on the rings for reps, you are not weak.
Lower body strength though, no, the iron wins that one. Trained elite level gymnasts can actually deadlift in some cases triple bodyweight, but they can't squat near that number. Extra leg mass is detrimental to ring moves.
In my mind, when I hear calisthenics I hear street workout, as in endless dips chins and pullups with a vomit inducing level of volume for the uninitiated trainee. Nothing wrong with that style of training, K Boges on youtube has some serious definition and athleticism with his simple diet of bodyweight squats, pushups, and pullups, but you will not be THE BIGGEST you possibly can be without picking heavy things up off the floor or squatting heavy weights. Not everyone wants that kind of size and there is definitely a feeling of freedom from using your environment (the ground, bars at the park etc) to get jacked. My favorite part about lifting is that there are a thousand different ways to do it and with enough effort, they all work.
I haven't touched weights in 10+ years, but I can planche & it's said if you can planche you can bench 2x your bodyweight. It's likely that I'm a lot stronger than an equivalent lifter of my weight. I do train weighted pullups, I can front lever & can confirm a front lever translates to bodyweight + 65% on weighted pullups. Not sure what my weighted dips are, but a lot. Not sure what the equivalent overhead press is for a freestanding handstand pushup, but again, a lot, probably at least 60-70% of your bodyweight.
Especially the straight arm ring movements are going to have wicked direct translation to weights. If you have the genetics to go beyond street workiout & hit real deal gymnast moves like maltese, victorian, iron cross, etc your natural biceps will probably be much bigger than a weightlifter, as gymnasts are famous for their biceps & calistenics is poor man's gymnastics.
And abs? How do you even work out the entire range of ab/lower back muscles without bodyweight movements? IME - 6 packs aren't "made in the kitchen", you chisel that through years of dragon flags, levers, etc & these movements aren't possible with only machines/weights.
The downside to this is calistenics progress is much, much slower than just lifting weights.
One of the biggest benefits of calistenics is the community, even in globohomo NYC or Miami your barparks there are filled with regular street guys. The culture is completely different than that of commercial gyms.
Did you achieve a full planche with the recommended routine or did you use other methods, like Coach Sommers's material or Steven Low? If you go on the gymnastic bodies forums, they make it sound impossible to get to full planche without Coach Sommers methods.
Kind of a ramble, I have a theory that there is a hard cap to the amount of muscle a natural trainee can carry, and if he does for example gymnastics, his upper body will be bigger than if he did an all around weightlifting routine due to less emphasis on leg development.
I don't have the means to do a large scale case study, but my old highschool buddy for example got 19 inch arms and an absolutely massive upper body purely from bodybuilder style calisthenics. His legs by comparison look and are fairly average. I wouldn't be surprised if he could bench more than he could squat.
