1. Cul-de-sacs and surburbia lack through-streets. So it forces heavy long buses to navigate winding narrow loops. This makes your routing complex and slow.
2. When commuters travel suburb-to-suburb instead of hub-and-spoke downtown, origin-destination pairs are too scattered to support fixed routes with meaningful frequency.
3. Low passenger volume per mile makes fixed-route bus operations financially unsustainable.
4. Disconnected street networks and long setbacks force residents to drive just to reach a bus stop. Like seriously pull up google maps. There are a million suburbs in the greater DFW area where you need to walk 15 minutes just to get out of your neighborhood to the nearest main road where a bus stop would be placed. When it's a thirty minute round trip of walking, (not to mention what the walking situation looks like at your destination), and you throw in stopping at every bus stop on the route, every commute takes several hours instead of 20-30 minutes driving.