The main problem points for incompatibility are places where the car interfaces with software outside of itself. As that software gets updated or APIs change, the car can go out of date. I think chargers and automatic payments might be the most important one there.
Why did Chinese companies jump into the car industries producing cars when they didn't have the know-how before? simple, rent seeking. Chinese government was offering incentives to do so. https://reason.com/2023/08/23/chinas-e-v-graveyards-are-an-i...
A “life and death race” has begun to unfold in the world’s largest market for electric vehicles - https://www.cnn.com/2024/04/24/business/china-ev-industry-co...
The first generation Model S still works just fine at Superchargers. Any EV you buy today is even more likely to have support a decade from now.