If it makes people feel better I have had to regularly remove links from stretched Stihl chain brought to me by farmers etc (90% of people in my area run Stihl saws as the dealers near have a monopoly).
This has absolutely nothing to do with the chain quality but everything to do with people that flog the guts out of a blunt chain and turn their oilers all the way down to save 5 cents on bar oil. These guys also have massive bar wear, on one side, and have absolutely no idea on saw maintenance or chain sharpening.
The only time I have had to remove links from any of my well maintained chains is when I've spun them up 1DL too long and haven't left enough bar adjustment
All chains stretch excessively when abused, regardless of the brand. My father in law is a classic. I have had to remove 2DL from a 66DL 3/8" Stihl RMC chain with cutters still at 80% (on a number of his chains - this is not a one off). If it doesn't cut he just pushes harder instead of sharpening it and he always runs the old 029's oiler in drought mode. Getting tight with the oil is actually counter productive as chain and bar wear goes through the roof. Oil is cheap - bars, sprockets, and chains are not.
In my experience if cutting dirty hardwood Stihl's semi chisel will outlast Oregon. In full chisel I do like Oregon's LGX but prefer Stihl's RSC - both are good chains.
One thing I will say about Stihl chain though is that it ALWAYS oozes European quality straight out of the box.