Photography is one of the few art forms where so much emphasis is placed on the technical side of the craft. As to similar results with a multitude of of processes it relates to my investigation into shooting wet plate collodion. As you look at the work of wet platers you begin to see work by some that is so flawless in their technique that you do not see much difference from a print done on film, especially if they are enlarging onto modern paper with a glass negative. I know that one of the "advantages" to collodion is it is grainless compared to film, but how much grain is there in an 8x10 contact from 100 asa film?
As far as the look of a plate with swirly bokeh, and limited depth of field that is a product of the lens being used which is pretty much predicated on the limitations of the speed of the collodion (asa 1). The glass plate or tintype is itself an art object so that adds some to the appeal, but as far as a final image you can get near identical results with film, vintage (and some more modern) lenses and filters at a fraction of the trouble and cost.
But yet there are certain practioners of wet plate (and other processes) that just seem to be able to get something out of their process that others can't and cannot be duplicated or approximated in other mediums. I think this is where hobby evolves into craft which evolves into art.