I think they feel fantastic, especially performance fabrics during summer. Falls apart, depends. As thicc thigh toucher, I rub through cotton/denim within a few months. Unless I reinforce crotch area with sacrificial patch. I've never worn through stretch fabrics, hence no need to repair. As someone whose weight fluctuates, cotton also gets stretched out.

Other than that, good moisture and odor control, comfort/mobility of stretch too much of life upgrade. Also fairly wrinkle/iron free. I'd take convenience over durability anytime.

I will say synthetics haven't been able to replace bed sheets on most of criterias above.