Society got more casual and so did the mob.

Most photos available today are taken when guys are being walked in by the feds or after they’re released after being charged. It’s incorrect to judge them solely based on how they look like when they get picked up. When that happens keep in mind that 1) they’re in the early hours of the day 2) you don’t want to seat in handcuffs all day while wearing your best suit 3) you don’t know if/when you’re going to be released and don’t want any of your belongings to become souvenirs for federal employees.

Street surveillance pics taken in recent years show them as regulars dressed according to their age and location.

The mob always had a fair amount of slobs, lower caste guys who were not up to “fashion standards” compared to others. Not everyone was Castellano.

Their attire during trials (if allowed by the court) and during social events like out-of-the-can parties, weddings, funerals, crew/family dinners, etc is still unquestionably neat and formal.