Source? Anecdotally, GPUs sourced from cryptomining were absolutely fine MTBF-wise. Zero apparent issues of wear-and-tear or any shortened lifecycle.
If you are running a gpu at 60C for months at a time, but never idling it (crypto use case), I would actually hazard a guess that it is better than cycling it with intermittent workloads due to thermal expansion.
That of course presupposes effective, consistent cooling.