There's not enough data to make any useful statements about an ID.4's value so far out in the future. It's unpredictable. You just never know what's going to happen. One thing that's relatively certain is that it will lose value, but even that you can't say for certain because the future is... ummm.. unpredictable.
One piece of anecdata I can provide is that 3 years ago (2018), I bought a new VW e-Golf SEL for $32.5k. I got the full $7500 tax credit plus a $2500 state cash rebate. So, final cost was $22.5K after the credit and rebate. In the 3 years and 35,000 miles I've owned it, it has run like a champ, no accidents, no breakdowns, and as far as I can tell, has little to no battery degradation (in any case, there's an 8-year 100,000 mile warranty on the HV battery system). Out of curiosity the other day, I went up to Carvana's web site to see what they'd offer, and their offer came in at $21,800. Back in 2018, I'd have never predicted this. In fact, my brother chided me back then for buying rather than leasing because "in 3 years your car's tech will be outmoded and the car will be worth less than half of what you paid for it." So my takeaway is that you can never tell, so I just try not to overthink things that are out of my control anyway.