This is basically true. but part of the trouble is the ignition switch and the switch connector, and if using heavier headlights, the load on the headlight switch and connector and the dimmer switch and connector. Only thing you have eliminated is the bulkhead
The argument "for" relays is to simply look at modern cars.......many (most?) modern cars use an underhood relay / fuse panel to shorten wiring and reduce loads on wiring going into / out of the interior.
