Narita Express had wagon sales onboard till March 2015. Reason JR companies are giving for decline in sales of wagon sales onboard is that convenience stores at train stations become norm and passengers are buying drinks/snacks/food/obento before boarding a train at a station where convenience stores at stations have far larger selections.

I do not think many here on FT ride Kodama on Shinkansen, the train which makes stop at every station. Wagon sales on Kodama is gone now, and buffet service which used to be on Kodama was ended on 2000. However, Kodama makes 5 min. stop (sometime 10 min. stop) at stations to let Nozomi running behind to pass. It is easy to get out on platform and buy drinks, snacks, and bento with local flavor. Kodama is far slower than Hikari or Nozomi but little fun riding on Kodama stretching legs out on platform and having bento with local flavor, if you are not press with time.