What about the American Bar Association, American Medical Association, and other similar groups? They're maybe more like guilds, but they also do a lot of lobbying on behalf of their profession, and provide group insurance and other services.

Professional associations don't do collective bargaining and aren't labor unions.

While professionals can have unions (and many public sector professionals do), professional associations are structurally not inclined to be union-like because a substantial share of their members -- and usually their most influential members -- are employers, not employees.