Male lawyers still wear carefully tailored business suits even when the rest of the business world has gone more casual. Female lawyers likewise tend to wear a higher level of business attire than typical in other office environments.
Language is also more formal; I had jury duty once, and the defense lawyer mentioned his client by first name. The judge reminded him that they address people formally by last name in court. (That guy came off like a relatively new lawyer working his way up in the public defender system; Trump would probably be better off hiring him than anybody he's actually getting, but that guy is also probably smart enough not to.)
How lawyers present themselves in court and in front of clients is very important. A gaming laptop with unicorn puke RGB is not a good look.