Main diff between then and now: Every op seemed to wear a coat and tie.
That likely has more to do with the way photographs were treated in those days.
The "snapshot" or casual photo was not all that common, equipment had to be set up in order to take a shot, often involving not only the camera and lighting, but portable darkroom as well in order to process the plate on site.
What with all that going on, people tended to treat the photograph more like the situation where they would sit for a painting - and thus would dress up for the event.
That does not necessarily mean that the same gentlemen would wear suits all the time when operating their amateur gear.