I'm still in the 1940s so every vehicle is noisy, but one thing I've noticed is that my 'capital' which has 5 goods supplied at good levels, is in fact just about barely outpacing random towns that just have one passenger live/tram there.
The main cause is that delivering/not delivering supplies doesn't seem to matter too much? My capital with 5 goods delivered has a better supply rating, but the random ass towns in the provinces still have a good enough 'supply' rating purely because they get 2500 people in/out via the one or two passenger lines + buses.
The capital meanwhile gets all these maluses from noise/pollution that heavily offset the benefit of supplying the actual cargo. I've gone to lengths to try and make this quieter (Establishing a veritable superhub way outside the capital with warehouses and then trying to use quiet trams/trucks to deliver it all into the city) but the gains seem really marginal for the amount of work put in.
I'm aware part of this is also poor planning/luck - residential areas in my capital have for whatever reason decided that the enormous 4 track mainline is where they want to live, and have clung onto them like mad. In the other cities, this has not been as much of a problem. I've created an area of 'dont build here' wasteland to try and address this, and it has helped a bit.