At 6 feet / 183 cm that it takes 184 lbs / 83 kg to be overweight. From what I could find, for regular gymgoers the typical weight for people around 6feet is 180-190lbs, which put many people around the overweight threshold. I am myself at 24.9, and while not skinny I am definitely in the skinnier half of the people at my local gym.
Yeah really well muscled guy being BMI 27 is probably ok but by 30 it's not natural muscles that are making the scales go up.
And obviously genetics matter, but it look at master level soccer players: athttps://pmc.ncbi.nlm.nih.gov/articles/PMC6239137/