My collection of 20+ year old T-shirts does not support this hypothesis. my experience has been the agitator in the washer is what causes the most damage.
Lower quality towels have a very loose weave that easily comes apart both in the washing and in the drying. Some of the very worst, in my case Eastern European, towels are so bad that they show near bald spots after just 3 washing cycles.
I can't see any problems with this; those are tiny fibers and they don't make a big difference except over years. It doesn't affect the weave that much.
What causes the most damage to my old T-shirts is deodorant stains. :(
For shirts I run through the dryer, they don't seem to have suffered much by it. But I don't run printed designs through the dryer, because they take serious damage that way.
Most of my T-shirts survive this (and I love having things come right out nice and dry) but there are 100% cotton and 100% wool clothes that shrink. I try the lower temperatures but the only real sustainable way I found was to lose weight continuously so I can fit in them. The others I just send to the laundry guys. Don't know what they do but it usually comes back nice.
Considering how popular synthetics are these days, I suspect it's because they use small combo washer/dryers in Europe. Certainly my British washer/dryer combo did a good job.
Damage of clothes through the washing/drying cycle is mostly the result of the kinetic energy they are exposed to in the process. Keeping a lower net weight load, and reducing the rpms in the spin cycle can have a large impact on longevity.