i can only speculate because i can’t play, but i think it would be useful especially in the beginning if people focused on an area and built their lines so that trains can share tracks and all lines complement each other.
in a lot of videos i see lines scattered throughout the maps and people jumping all around the map connecting some industry here and then some there and then a passenger line somewhere else. in that case trucks and busses are obviously better.
maybe if you’re doing it more like the real early railroads, connecting a few cities along one line and the adjacent industries it would work better because it reduces building costs. also having one line to serve cities A-B-C-D is much better than to run three lines running from A-B, B-C and C-D, because the latter introduces long waiting times when people have to change trains. yet most people actually build their lines to the latter principle because they introduce a new line whenever they extend their network.