He’s not actually very fashionable
The Bond franchise is known for some seriously slick looks and bespoke suits. It’s not actually Bond’s style in the books.
I mean, he does get custom suits, but mainly, he’s a relaxed dresser. In fact, more often than not, Fleming describes Bond as wearing “well-worn,” “comfortable,” and “battered,” suits, paired with moccasins/loafers. This was virtually unheard of in 1950’s London, as most people tried to dress to impress and wore appropriate footwear. But it gets worse.
Paired with those suits, were dress shirts with short sleeves and breast pockets for his cigarettes.
Sounds totally suave and sexy – a mis-matched, chain-smoking, alcoholic.