Resolution is surely a very diverse beast. You can create a picture 1 pixel large or infinitely large. But in this day and age, with computers, our resolutions can be anything, as long as the processor and ram support the size.
I myself use a considerably small resolution for my comic and my other works. Most comics range way higher in resolution compared to mine. I chose to stick with no larger than 4000 pixels high for my current resolution, because it just gets to be a lot to manage with a trackpad and mouse.
I also use a line width of 3 pixels, because most scanners at 300dpi pick up my pencil lines about that size. Also I like the more pixelized look. It creates a space that feels more gamey. I grew up playing PS2 and Gameboy and DS, so I enjoy the look. I came to appreciate how no matter the resolution, you can still make a good experience.