I believe that muscles/having a fit body are not at all overrated. However, I also believe that most men overestimate how much muscle they need to have in order to look attractive and may go for a look that is actually unattractive to women, this could be due to bulking to the point where you literally become fat or going on a cycle that takes you into juicehead territory.
I'm 6'4" and currently around 240 and strong but also very fit overall. This is a result of my genetics, I naturally am broad shouldered and gain desne muscle easily. I've never used steroids before and would be much larger than what the vast majority of men could ever attain. Most men would struggle to get a build like mine, again due to genetics, and it wouldn't be in their best interest to aspire to achieve that, if it was even possible.
Women like fit and strong men but will have a preference on a particular end of the spectrum. Some women may really like a guy that looks like a rugby player or tightend type of body, solid muscle mass and just tall and strong. Other women may prefer a more slender but muscular build, like a swimmer or a guy that runs track. However, I feel that when you start getting towards extreme ends of either spectrum of athletic builds women don't find it as attractive. Think of an elite endurance athlete, particularly a marathon runner, that is incredibly skinny.....most women wouldn't find that attractive. On the opposite end, think of something like a heavyweight powerlifter or an NFL lineman, a lot of muscle but overweight, most women wouldn't be into that either. Women also are not typically attracted to the geared out of the gills look like you see in bodybuilding, it's gay men that are into that, which is an entirely different topic to get into lol.