> I can still run just about any modern AAA game at the highest settings.
AAA games mostly target the console. Look at GTA5, which isn't even out on the PC. Most AAA games will run on a PS3, which came out in 2006, and has 512MB of RAM (combined system / graphics).
That said, there's a point of diminishing returns - making games look much more realistic will take obscene amounts of resources.