I don't think we've reached the point yet where EV values fall off a cliff edge, but as soon as it becomes clearer when batteries fail, and the scrap/recycling issues become better established, this will show the true environmental costs.
Tesla guarantee their EV batteries for 8 years and re-cycle batteries into their domestic "Power Walls".
There are enough early Tesla Model S vehicles in North America with 200+k miles and 10 years use with batteries that don't yet meet the Tesma definition of "not fit for use" to suggest battery life will be no more of an issue than ICE Engine life.
I don't think EV depreciation will differ from ICE car depreciation.
