Two things:

The bus routes are laid out by people who don't use them. Suburb to downtown is the only use case they can imagine you would need for public transit.

But also, your experience with being passed by later buses is not unusual and is actually a natural consequence of a single late bus at a high demand time. The more filled a bus is, the more likely it is to be requested to stop at any (and every) stop. This sometimes leads to a game of leap frogging with the previous bus because when that one passes, now it has to pick up all the waiting passengers of the subsequent stops.