But you still have it backwards.
We could very easily design and build a car that lasts 30 years. But we don't, because manufacturers don't want them to last that long.
Evs don't have transmissions, or complicated engines, and the wear on brakes is much less with regenerative braking.
Other things like air conditioning and interior coverings could be easily servicable
Why should the life of an ev by limited by its battery?
So far most ev batteries do much better than cell phones, as long as they have cooling.