You don't need a darkroom to process B&W film, a changing bag is all that is needed for loading the film into a developing tank. The advantage of developing the film yourself is that you can take develop for extra fine grain, or speed increase, or increased or decreased contrast etc. If you scan your film then the only additional items needed are the developer, fix, a thermometer, measuring jugs, a supply of hot water, somewhere dustfree to hang the film to dry and negative storage sheets.
C41 type B&W developed by a automatic process can be convenient if you want prints quickly but you give up control of the final result. The prints are often on colour paper and can end up with distinct colour casts if the equipment is not adjusted correctly. Also you are probably depending upon someone who either has little experience of B&W prints, or who just does not care much, to assess the results and make any exposure corrections. I would expect a professional lab to be staffed by persons who care about the results and are able to get the best from your negatives.
The best way of all is to print the films yourself, you then have total control from determining the exposure in the camera, development of the film to manipulation in the printing process to obtain the results that you want.