Unless I see some real measurements on that chain that was ridden for 4,000 miles with no lube, all the statements about how well it's working are meaningless. Chain and cogs wear in together and will function adquately for a long time when there is no shifting involved.
When I do a chain wear test, at the end, I know how much elongation the chain has suffered, how much the rollers have worn (both OD and ID) and how much the side clearance has increased. I could make that same kind of ignorant statement about one of my 10 speed chains. I used one for 6,000 miles once and regularly checked it for elongation with a precision 12" scale. After all those miles, the length had not increased by more than 1/64 of an inch, or 1/4 of the "allowable" 1/16 inch per foot elongation. Did that mean that the chain could be used for 24,000 miles? Of course not. Upon more critical inspection, even though the pins and inner plate bushings were worn very little, the rollers were severely worn and the side clearance had increased to nearly twice the original amount. This chain was lubricated after nearly every ride.
The function of a chain on a 9 to 11 speed derailleur equipped bike is much more cirtical than that a single speed or internal geared bike, where no shifting is involved and the chain is never used at an angle. The only way that a single speed setup will fail is if the chain pitch increases enough that contact with the cog rises to the very tip of the tooth and breaks the tooth. Until that point I guess you could claim that the chain worked perfectly. In reality it was not working perfectly for a very long time prior to that.