The film infrastructure is very different between countries.
Here in Germany (and most other European countries) minilabs have never been installed in supermarkets or drugstore chain shops.
Minilabs have been (and still are used) only by local photo shops.
Drugstore chains have always used the big high volume photofinishing labs. Labs with 300 - 500 employees.
These gigantic labs are developing thousands of rolls of film each day, and make RA-4 silver-halide prints. And deliver RA-4 prints from digital files (as online service).
So you put your film in the envelope in the drugstore chain shop, and about two days (or sometimes a little more like now in fall / winter with less photographic activity) later your developed film (with prints) is back.
Cost for developing and prints are extremely low here in Germany.
All drugstore chains are offering this service (including E6 and BW).
In Germany alone there are at least seven of this high volume mass production labs:
CeWe is operating several, Fuji Eurocolor as well, and OrWoNet, allcop, dplab.
With more than 3500 drugstore chain shops we have "at almost every corner of the street" a possibility to get our slide film, negativ film developed.
And of course the local photo shops offer development and prints (minilab and send out service).
And most of the professional labs offer nationwide (or even international) mail order service.
Cheers, Jan