I think you're missing the point. The Hellcat is not a commercial success despite its high residual - there's just not enough broad market demand. The Model 3/Model Y sell hundreds of thousands of units and the market sees enough of a future in the Tesla lineup that its currently the most valuable automotive company ever by a factor of 2X.Every one they can make.
In Florida, they are going for 20,000 dollars over MSRP.
Its natural for all of these cars to become obsolete over time.