Movies and TV have in recent decades really leaned heavily into a level of muscle that isn't possible for the average person to attain without performance enhancements. This combined with gymfluencers who take performance enhancers and people who's hobby is lifting so they spend many hours a week at the gym plus average people not having the time or money for the gym makes a perfect storm of most people not knowing what a healthy amount of muscle or a healthy build looks like

Oh and expectations have always been for women to be overly thin so far too many women are led to feel that their healthy weight isn't skinny enough