The brightness plays a big role re: the power consumption. For example, the Halloween color chaser on our paper mâché UFO ran at a 4 out of 255 brightness setting. The 4A power supply handled all of those LEDs without issues and I simply daisy-chained 3 strips to each other to supply the necessary power. Obviously not something I'd attempt to do with a higher power load.
But voltage drop is not to be toyed with. In a former life, I pulled 1/0AWG wire through a boat for a windlass to ensure it had a good power supply. Bit of an upgrade from the corroded 2 AWG stuff the OEM put in. In fact, I got to rewire the whole boat because of British wiring practices. Real bus bars are a big plus, especially when bringing all the GND connections together in one spot.