They would be if the makers had the parts widely stocked. One of the issues with Tesla, at least in the past, is they pretended to have nothing to learn from Toyota and Honda, and there just weren't any ball joints, control arms, and wheel bearings on the shelves. Getting your Tesla chassis fixed is a 2-hour job with a 6-month waiting list.

That’s interesting. I had the upper control arms replaced on my model 3 a few years ago. It was a 1 hour job with a 1 week appointment lead time, and that was because I got a mobile appointment where they came to me.

Can any service replace them, or only official tesla(tm) one? Is there a healthy ecosystem of original oem parts and good 3rd party ones?

I'll never buy a car that a random service cant fix, bmws for example so far seems easy peasy to achieve this, which brings TCO almost down to cheap basic brands.

Anyone who has the necessary training and equipment can repair or replace an EV battery and it is done by a few companies here in Norway.

for instance https://www.batterielektro.no/elbil/, https://carfix.no/carfix-teknikere-kan-apne-og-reparere-elbi...

And much much much cheaper too