I have to disagree with you. I usually start with trains for all cargo supply and use trucks only for distribution. Of course, you should make lines as long as current engines can get, and morover you should load it properly. You can see a screenshot from 1853 (Hard difficulty, no mods at all) with cargo line making profit (this line delivers only coal w/o iron, so the recent update doesn’t affect the balance here)
Here is the same line when General locomotive appears
And to demonstrate that this strategy works well, here is the same map 79 years from start
