56k TPS is a supposed peak at burst volumes, in reality the number is closer to 3K TPS but that's beside the point.
Until there's a real need for bitcoin to support this sort of volume (if ever) I don't think comparing bitcoin to visa tps wise proves anything.
If there's enough customer adoption where there's a need to handle that kind of volume you can rest assured there will be infrastructure to support it and instead of a loose group of "core devs" there will be an official salaried department (at visa? :) ) working on this full time.
Until there's a real need for bitcoin to support this sort of volume (if ever) I don't think comparing bitcoin to visa tps wise proves anything.
If there's enough customer adoption where there's a need to handle that kind of volume you can rest assured there will be infrastructure to support it and instead of a loose group of "core devs" there will be an official salaried department (at visa? :) ) working on this full time.