My (anecdotal) evidence was that I replace my regular car battery in my cold-weather state every few years, and it does barely anything! And my sister just replaced the main battery in her 2006 Prius.
On a more applicable note, a Leaf loses 33% of its range after 56k miles [1]. I'm not nearly as familiar with Teslas (unfortunately); perhaps they have cracked the formula to long-lasting batteries.
[1] https://www.nimblefins.co.uk/nissan-leaf-battery-capacity-ra...
The Leaf and Tesla both use lithium-ion. I don't know why the apparent difference. But per https://www.tesla.com/support/vehicle-warranty-m3, Tesla's battery warranty is 8 year or 120k miles, and comes into effect if your range drops by 30%. So they expect better performance than the apparent real world performance of the Leaf.
I also do not know why there would be a difference in those technologies.
That's a lot of regular maintenance that just went away.
Per https://cleantechnica.com/2018/04/16/tesla-batteries-have-90... real world data suggests that Tesla batteries are operating at better than 90% efficiency after 100,000 miles, and are projected to be operating at around 80% efficiency after 500,000 miles. The often repeated claim that batteries will wear out faster than engines is contradicted by the evidence.
There isn't enough real world experience to prove it, but electric motors are physically simpler than internal combustion ones and it is believed that few electric motors will need repair before hundreds of thousands of miles. That gets rid of more big repair bills that car owners face.
Consider that as https://www.yourmechanic.com/article/the-most-and-least-expe... points out, the per year maintenance on a used car is generally $1-2K per year.