ICE's are conceptually pretty simple. Anyone who has built a computer should be able to do basic car maintenance if they want to. The electronics is what makes newer cars more complicated, and I assume EVs even more so.
It’s ridiculously easy to look up a part number, order it online from wherever is most convenient, and follow the steps in the manual to replace it.
Most parts could only come from Tesla, including the Bilstein struts (a part number Bilstein refuses to sell to anyone but Tesla). $900 per corner.
USB port between the console? $400. I found a used one on eBay, fortunately.
When the wheel rotation sensor receiver went bad, it cost $2500 for them to install and reprogram the replacement, because they "upgraded" to a different mfr. When that one started to go bad (water ingress, which wasn't cured by the new part), I sold the car and said good riddance.
A lot of Americans become very low IQ in the context of any car related financial decisions. Off loading their vehicles is one of the classic examples of this. Do NOT sell to your dealer. Carvana is the only exception and only because you can easily offload messed up cars to them without disclosing it.
The other thing is that it's not always low IQ, but many people value simplicity. Do I want to show a car, deal with cashiers check fraud, flakey people, etc... or do I want money literally right now? I've sold cars to CarMax and I've sold cars and boats privately. The private price I think I can get has to be considerably more than what I can get with zero hassle.