Not saying your points are untrue but for completeness you would expect less for a cheaper car. We can certainly point to the technology gap between the two being too wide but at the end of the day they are not at the same price point.
I can buy the cheapest, junkiest gasoline powered car and still have ready access to fuel anywhere I need to go. That's what EVs have to compete with.
I actually think Tesla propped up its resale values in the beginning with the guaranteed buyback price thing. They managed to maintain this until people started getting used to "tesla is expensive". (although teslas are more useful because of the large battery and charging infrastructure)
I am uncertain about this. They've tried this with phones, and it ends up that the cost gets bundled into a more expensive service. Also changes might be forced to get people upgrade more often and make the devices throw-away.
I think with ownership, there might be pressure on the manufacturers to focus on longevity.