That’s a problem if the public transit system is solely geared towards sending people to the center. As a counter example there are lines in Tokyo that take different paths, like JR Musashino and Nambu lines, which do a big arc in the outskirts, or the Tokyu Oimachi Line, that does a line through southern suburbs, to name a few. Buses also fill in connections between lines that lack a direct rail connection (or you can go with scooter/bike shares)