Depends on the kit - in the case of Lizardmen you're right, customisability was limited to flat revolute arm joints, but kits like the now-departed late 6th Edition Dwarf Warriors and the current Skaven Clanrats have ball-socket arm joints, and older kits like the long-gone High Elf Spearmen and Orc Boyz had both flat revolute shoulder-arm joints and also torso-leg joints that allowed you to rotate the bodies (in the case of the Orc Boyz this was ball-socket for maximum poseability).
This is still more though than the decreasing customisability of the current GW kits, where a lot of the time there are arms and (most pointless of all) separate legs that only fit on one model.