Are they really, though?
A 2021 Model 3, Mach-e, Polestar 2, Model Y, F-150 Lightning, e-Tron, or ID.4 (to name just a few) are not too different from the ones sold today. Aside from software updates and minor refinements (mostly DFM), I don't see much progress. That's not a problem, since they're all competent vehicles for single-car households.
Several 2025/26 models have even been de-contented compared to their 2021 selves.
Trying to steel-man your argument a little, the only models I can think of with significant progress are the bZ4X/Solterra (widely panned due to initially uncompetitive specs and pricing), Leaf (which has been getting small, incremental improvements for more than a decade) and the now-discontinued Bolt (which was the cheapest road-tripable EV).
I think you really have to be looking compliance cars that entered the market before the Model 3 and/or models that were acknowledged as uncompetitive when new to find significant/fast progress.
No, the real problem is that the true market-clearing price for most of these vehicles was $7500-$10000 less than MSRP (which was set knowing the regulatory environment), combined with the false calculation of depreciation based on MSRP instead of market price.