It is important to carefully read battery warranties. They are real but depending on manufacturer range loss of 20-40% may qualify as "in spec" in 8/100K. It doesn't say there will be no change in range and honestly that is to be expected.
The less cycles, the less time at 100% or low charge, the less overall heat all combines to how much range you can have later. But again keep in mind that a normal ICE car loses horsepower and efficiency over same time too.
Jaguar is 70% per the warranty, https://www.jaguarusa.com/about-jaguar/elitecare.html
But this does not mean every car will degrade to this level, this is what they set up as their worst case to minimize the need to cover all potential claims. We guard band against this number in the electronic world to ensure that only a small % will be affected if any.
Depending on the battery chemistry, a full discharge could be as detrimental to a battery as a full charge, such as in my LiPo mini RC vehicles, we cannot discharge below the threshold voltage, but charge to full all day long. We don't know the full chemistry of the iPace battery nor the BMS they use and hence the reliance on the warranty to guide how to charge and use the vehicle.
My LiPo batteries can be charged fast or slow and still have the same performance with minimal degradation, just not over charged more than their rating (1C, 2C, 4C, etc). The same is applying in BEV's, but much more complicated and driven by the manufacturers of the battery, BMS, and vehicle.
Agree as stated, ICE vehicles degrade over time as well, my AWD Ford Flex used to get about 350miles on a tank new, now at 120Kmiles and 11 years, it is down to 297miles, so all vehicles will give up some range over time.