Another data point for you:
I have done roughly 1500 miles on my indoor wheel-on trainer since the start of last winter - all on a carbon road wheel w/ 28mm GP5000 clincher tire. This tire already had 1500 miles of outdoor use on it at the start of last winter. This is what it looks like as of this morning:
This bike basically lives on the trainer and only sees a handful of outdoor rides each year. I see no evidence of accelerated wear from my wheel-on indoor trainer, and this tire looks only slightly more worn than the matching front tire. This tire looks exactly like what I would expect a tire with 3000+ miles on it to look like. I had planned to swap the front and rear tires at some point, assuming the tire would be severely worn based on the internet "consensus" on this topic, but I'll probably leave them as-is for a while longer.
These Conti tires cost about $50/ea, vs trainer tires that cost $30/ea. In a few years when I eventually wear both of them out, maybe I'll consider a dedicated trainer tire, but I doubt it.