Totally agree. All these analyses that determine the "money factor" or true interest cost (down to the basis point!) just serve to obfuscate what's more important. Since the residual value assumption dominates the lease-or-buy decision, it's important to figure out what it is for you.
For those of us who can pay cash, we can use our opportunity cost of funds as the assumed interest rate and back out the implied residual value. For those of us who need to finance the car, we can use the interest rate for a standard car loan as the assumed interest rate. That cost of funds might be 3% or so higher than the opportunity cost of funds for a cash buyer.
As kort6776 said, electric cars historically depreciate at a faster rate than ICE cars, so their actual residual value has been quite low. My sense is that assumed residual values for leases have been higher than actual residual values, but I have no hard data.