>but my dad played for Syracuse in the The Express era

People in pro sports take PEDs.

>can be very physically active and muscular but still pretty fat.

you can retain higher muscle mass at higher bodyfat% like Sumo Wrestler.

being lean limits amount of lean mass you can carry.

>Yeah I know bodybuilders manage to get jacked and many of them are doing nothing

bodybuilders who take PEDs do not easily gain fat because steroids change nutrition partitioning.

also, some bodybuilders take DNP, clen, t3 etc... but many bodybuilders also do hours of zone2 cardio.