At my auto center I once had a customer who had 112,000 miles on his tires and they still had 3-4 32nd's of tread left! (The legal limit is 2/32nd's). I was absolutely
astounded. He did take very good care of his tires though with regular rotations, rebalancing, checking the air pressure every week and regular wheel alignments. He drove a lot of miles per year, something to the tune of 40,000 miles and it was 95% highway miles he accumulated commuting to work and back.
The tires were the General XP-2000, which was a wonderful tire that isn't made anymore, sadly.
General does make some very good tires and at a reasonable price.
But generally, most tires will last about 40,000-50,000 miles with the use, (or abuse), that most motorists have with their tires.