Tesla simply realizes that shit happens. You can be following at a safe distance for normal driving, and still hit shit because it fell off the truck in front of you, or you just never had time to see it till the vehicle ahead ran over it also. And of course, harder to see such things at night till you are closer to them.
I've driven over ladders, pallets, and loose 2x4's. I've had very near misses of crap spit out of the wheels in the lane next to me, so suddenly a tire, a 2x4 or what have you is bouncing into your lane. I'm not that dumb, that I'm going to jerk the wheel at 75 mph. That's how you go over the barriers upside down. Hell yeah you swerve, but not too fast or too far for that speed.
If you are driving the open road, without being surrounded by semi trucks, then you can easily see and avoid. But you don't get to drive like that much on I-10.
If on city streets, speeds of 45 mph or less, then of course it's quite easy to not run over a ladder. But on the freeway, even following using the two second rule, you won't have much time to avoid any object that covers your entire lane.
Just try to use the 2 second rule in LA. If you do, two cars slot into the huge space you tried to leave in front of you.