i find overcoats a bit of an anachronism. 21st-century city-dwellers spend most of our time indoors. the moments when we're out are typically not long enough to require seriously heavy protection. (i do realize that if you are in places that get REALLY cold, even 10m outside can be painful and an overcoat can help. but for the average european / american city that isn't far north, i'm not sure that level of protection is required, even for a lengthy stroll.)
overcoats also get dirty. and in my case i tend to forget my coats and lose them. a nasty habit.
i also find them too heavy and annoying, unless they are made of a very light, cashmere-like material. and i never wear an overcoat when i'm out of a professional situation, as my legs never get cold. i really only wear an overcoat because a short coat on a suit can look goofy.
in general, i am happy to pass up the fleeting moments of sartorial gravitas that an overcoat confers as they are more trouble that they're worth. i own 4 and that's two too many -- for me, anyway.