I guess reductio ad absurdum could work in reverse here. Let’s say a lifter flat out refused to do dumbbell bench, could he or she not get jacked? We can look at people that don’t lift as a clue to answer that, I don’t know what different athletes do or don’t do but I’d be surprised if there isn’t at least one gymnast that don’t do any real weight training that does looks jacked.
The question that follows there is, what could they do if put to the test? Apparently 3x bw deadlifts