The problem is repairs, you are held hostage by Tesla, so even a fender bender turns into a write off, or months without the vehicle whereas a normal shop could fix it up in a day with regular parts.
I'm all for hating on Tesla for legitimate issues, but the driver of that car crashed into a concrete pillar doing in excess of 120MPH, which probably has a lot more to do with why they died than anything else. Fires and being trapped inside mangled wreckage can happen with any vehicle, especially at speeds like that.
A high depreciation cost is a benefit to the company, since it can otherwise offset income earned elsewhere in the company, thereby increasing profits over what they would have otherwise been.
They're selling these for another reason than depreciation, but the comments here already seem to get that.
High depreciation is only valuable if there's no additional cost associated with them. Teslas have high repair costs (and opportunity costs as it sits idle waiting for the dealership to get to it) and, since they're selling them, there's now a replacement cost.
It's just when a business makes an "investment" aka cost, depending on the type of cost, they can use all or part of it (depending on classification) to offset "revenue" aka income, the more they offset then allows more income to be untaxed.
If you have a situation where a business has an asset (Teslas here) where the real life value (market value) suddenly drops, that business has to report additional depreciation, which does hurt the asset side of the balance sheet, but improves the income side
I don't have any insight into lender agreements, so it could be something else entirely, like the lenders would want the rental company to add additional collateral if the value of the cars drops.
I'm just saying that it's likely those other reasons driving the Tesla sell off.