You're trying to talk about two different things, hand drawn or painted art verses computer generated art. If you know how to do either they're probably similar difficulty. a 3d artist has to be wary about lighting and placement of objects, and unions of shapes, etc. a 2d traditional artist has to worry about the same things only a bit differently, where as the 3d artist has to figure out things more mathematically the 2d artist deals mainly with what he sees visually.
And about resolutions, i can prerender my graphics in 3d for 320x200, and it will still look okay (and yes high res still always looks better), this doesn't make working for one or the other any harder.
The only thing that's harder is when you're trying to do a paletted image verses a non-paletted one, and even that's not hard if you know how to manipulate colors, and even these days programs will do it for you. and old windows 3.1 image editor, does great converting a true color image to 256 (8 bit) color.
Of course you need to be an artist to do anything decent for either.
This is like those people who say they can't draw. Everyone can draw, it's just most people's left brained logical thinking stops them from drawing what they actually see rather than drawing what they know. (This is why you get skewed perspective on some drawings verses others, because the left brain tells you a certain object, say, a table, has a top and 4 legs and that it looks this size, and then you draw it and it doesn't look right).
In any case, whether it's harder for you to draw at a lower resolution than a higher one, is really just a matter of your skill, you may be great at modelling, and texturing, and what not, but not do squat in drawing by hand. By the same token you could be really great at drawing, but modelling and texturing could totally just not work for you.
Keith
