First off, a dealership is going to offer you low because they will then need to mark it back up to market value so they can sell it and make a profit. You will always get the most money by selling privately. If you do a trade in some states will take your trade in value off the taxes you owe on the new vehicle, because dealership owners have good lobbyists and dont like competing against the private party sellers.
Secondly, the used market has come off its high horse from a few years ago and back to reality. If you have ever leased a vehicle, they always have a residual value of what your vehicle is worth at the end of the lease (and this is the price you will pay if you buy it out) and it is usually in the mid 55% of MSRP range after 3 years, so even manufacturers know that their vehicles will depreciate ~50% in the first 3 years. The EV used market is even worse right now than the F150 market thanks to Tesla's multiple price cuts last year. Imagine having paid $120k for a Model X only for Tesla to drop the price on a new one to $80k a few months later, and then see what that does to your trade in value.
