It is definitely a little deflating - and I can see it in the eyes of others who are dressed to the nines (like recently on vacation at an awesome resort in Cuba, when they saw other diners arriving in shorts and flip flops - which by the way so broke the dress code.)
Where I live, many women seem to love fashion and dress stylishly - whether it's on trend or some unique funky version of it - so I definitely am conscious if I'm dressed down, and it's more encouraging to dress well here. My closest friend often makes me feel closet-envy with her happening wardrobe, so it's a lot of fun to go out with her & get inspiration. I try to keep in mind, though, that she is a completely different size & body type from me (ultra slim), so I know our styles must diverge. Still, I like to admire her style, as I do with so many here on YLF.
There have been times when I literally come home from an event where I was so inspired by the personal styles and impeccable fits, etc., that I scoop up every piece of ill-fitting, dowdy, unflattering clothing I own and shove it into the Goodwill bag for drop-off the next morning! Maybe someone else can re-purpose them but I'd never want to see them again. So yes, it can be influential to see others' sense of style & aesthetic.