Problems with EcoTec 4 cylinder engines only?

I had a 2011 Equinox (totaled now because of a wreck) with an EcoTec 4
banger. I started having problems with check engine light (cel) coming on.
Got a cheap code reader and it showed issues with exhaust timing chain
solenoid. Research on Google and YouTube showed it was a straight
forward fix. I tried it and replaced both intake and exhaust solenoids.
Problem solved. Or so I thought. Cel comes back on. Connect the reader
and same code. I think to myself, maybe I got a defective set. I take them
back to the parts house and they give me two more. Problem solved. Here
comes the cel again with the same codes. This time I took it to my mechanic
and he told me it was the timing chain and the chain guides. My vehicle just
turned 80k miles. He tells me that these 4 bangers have timing chain issues
after 100k miles and that the timing chain guides are made out of plastic.
Plastic! What moron uses plastic for such a vital component that should be
made out of metal. My engine had to be removed from the car to do the
repair because they found plastic bits and shavings in the oil pan. $2,000 bill.

Now with all of these similar horror stories I'm reading, are all these
problems limited to these piece of crap EcoTec 4 bangers or do they also
include V6 engines too?