The busses ran a few times a day the trolley was every 5-10 minutes. GM had to buy the trolley lines and force them to use their buses in order to sell their unpopular buses.
Trolley’s had fewer routes because laying track was expensive, busses on the other hand ended up with vastly more routes but fewer busses on most routes. This meant that even with significantly more total busses people would on average wait longer but conversely they walk less.
The biggest downside to complex bus routs is they tend to be more difficult to understand and use efficiently. However, apps can really pick up the slack and let people leverage complex systems.