What advantage do you gain by putting texture maps into the RGB and alpha channels of another texture? I’ve seen some people do it online, where they might place a roughness map into the red channel, a displacement map into the green channel, and the ambient occlusion map into the blue channel. Which you can directly access in the material editor. I can see how this would reduce the number of maps you need to work with individually (1 compared to 3), but besides that, is there any advantage or aesthetic reason for doing this?
It just makes things more efficient
Reduces file size(space on disk) textures being a big component of game disk size, could reduce download size of game in half, then during game play more efficient, less memory usage as mentioned above, smoother running game experience.