I completely agree with those who've said that they carry just the tools that fit their rig. My personal exception is that I carry deep sockets in common lug nut sizes, as well as a handful of oddball lug nuts that don't fit my rig, but might fit someone else's. Tools can get heavy and weight can cause its own damage.
I'm not sure I agree with the "cheap tool" answer. Sure, they don't have to be Snap-On tools, but if that K-Mart ratchet breaks on the first use, things could go sideways really fast.
As for skills, gaining our own set of them is critical, and we all should work on them over time; but having a tool or two we may not know how to use might just be useful to someone who DOES if they come upon us in trouble.