At $4,000 I would have lost my shirt on the ESA. In 110,000 miles my out of pocket repairs have been less than $500.
It's always tricky trying to decide about these things. In my life as a whole, I have almost never purchased extended warranties for anything, considering they were unlikely to be worth it. But a car is a somewhat extreme case because of the potential costs involved.
In my case, I waited until my initial 4-year warranty was up. Tesla gives you 30 days from the end of the initial warranty to decide. Just before that month was up, I had a firmware update stall, and brought the car to the shop. Their initial diagnosis was that the MCU was failing and that it would cost about $2400 to replace it. So, they ordered the parts and we set a date for the replacement. Knowing I was facing that large a bill, I bought the ESA, figuring that the computer replacement alone would justify the 2-year ESA cost or half the 4-year ESA cost. I opted for the 4-year term, knowing that I was also likely to face more door handle replacements, at least.
But when the MCU service appointment arrived, guess what? They said I did not need an MCU, the problem was a corrupt file on my USB drive (which I later confirmed). But I left the ESA in place, knowing that I could cancel at any time and get a pro-rated refund.
A few months went by, and the MCU was steadily showing more and more signs of failure. In the meantime, Tesla lowered the price of the MCU replacement from $2400 to something like $1500. Eventually mine failed utterly and it was replaced, with the ESA cost being just $200. I still felt that the ESA saved me money on that, even though the MCU repair price dropped further a few weeks after that.
Coincidentally, however, at the same time, one of my rear parking brake calipers failed. I had not heard much about these failures, but the cars of mine's vintage have a motorized parking brake caliper that is quite costly to replace. I had both calipers replaced at the same time as the MCU repair. Without the ESA, the cost would have been something like several hundred dollars each, as I recall. So, in that one visit got more than $2000 in repairs for $200 with the ESA, and I am only one year into it. (And since then, I have one more door handle fail, so the repair was roughly half price with the ESA fee.)
I have owned my car from new, it has gotten regular service, I do not think I treat it roughly or neglect it, but stuff does fail and wear, so I feel the ESA is a reasonable investment.