Theoretically, I would like to see in a few decades if a Tesla engine lasts any significant amount longer than a standard well made combustion.
And batteries really take the place of the engine for a combustion car (they are really the heart and soul of the electric car, on which everything else depends). They are super expensive, and I have yet to see any battery tech that lasts over 4 years, and normally it is performing far worse than optimal at a fraction of that time. I think Tesla claims that theirs are suppose to last well, but still not anywhere near where a few years of wear is not a significant chunk out of their value.