Most endurance racers TRY to stay out twice as long and can't. We can't really hate on the AI THAT much.
However, I'll let you try to drive a competitive car against those 🤬 at Le Mans on sports tires. The second you get near them, they'll shunt you.

If I could chat with those AI, the first words out of my mouth would be: "It's a 24 hour race, you flipping 🤬 🤬 🤬 🤬 🤬 🤬 🤬 🤬 🤬 🤬 🤬 🤬 🤬 🤬 "
Hey, you're the one who brought up the Chicane.
I'm not sure I'd want to drive the cars for the 24-hour races on Sports tires either, but as always I'll figure it out when I get there soon. I do feel your pain with their violent idiocy for sure, believe me.
I hope you don't think I'm being argumentative, because I'm not. I've just had an itch to check this out for a long long time and you gave me an excuse to try it. Yes I'm sure it's been done before. Long post incoming:
I'm planning on running the 9-hours in the Blue RE Amemiya FD35 RX-7, one of the AI cars. Usually I'd rather not be as much slower on the straights as it is, but I'm enjoying driving it so I figured I'd run it. So I'm comfortable driving it by now and it should be good for the test. I put some Racing Mediums on to match them and set out to run the times that they do.
I was a little slow at first(it's tough to drive that slow!) so I couldn't catch the AI RX-7 and follow it, but I ran steady 1:00 laps after a couple laps of finding the rhythym and ran steady without gaining on them. I did eventually start gaining as their tires wore out, and I could still keep running the same times while keeping the tires silent.
The AI RX-7 pitted after 33 laps. My worst tire reached the level his was at on lap 38, the same lap as the Mine's Skyline pitted, and as I caught the long-running CT230 that inherited the lead. I kept going to see how long the car stayed manageable at that pace. I was able to keep running 1:01 laps through lap 40, then my left rear got too low and began causing problems.
I only ran one :59 lap in the stint, and that with slipstream. The AI RX-7's best was :59.5 to my :59.7 but I don't know how many :59s he did. Still, I think it was close enough to confirm that the kind of tire wear they get IS achievable if you drive at the relaxed pace they do.
I always wondered if they had some sort of bonus that made their tires last longer, but it seems they don't. I actually outlasted them at a similar pace, and used less fuel too. I could have probably run longer if I slowed down at the same rate as they did late in the stint. My car is stock besides a couple small suspension tweaks(most notably .05 rear toe), broken in but oil not changed since purchase.
I think I'll probably end up on Sports Mediums for the actual race, or else a LOT of ballast on Softs.