Fun to speculate. My wife has a film camera that we haven't used in nearly 20 years. When we got our first digital camera, we stopped buying film for the old one and forgot about it. Now we have great cameras on our smartphones, so we have forgotten about the digital cameras too.
Maybe this transition is too simple as a model for the EV transition. After all, the cameras we have forgotten over the years are small and still sit somewhere in our closets. They were never such a large investment that we needed to sell them or make special arrangements to haul them away. But one thing seems clear, from the perspective of early adopters, you can easily trade in, sell or give away your ICE vehicle when you replace it with an EV. You can easily forget about you old ICE. It's someone else's problem.
Internationally, we know that affluent countries tend to buy new cars and a large fraction of used cars get exported to less affluent countries. So affluent countries that transition quickly to EVs could simply cast off most of the aging ICE fleet. Forgotten.
But this raises questions out the countries that import used ICE. Will they become flooded with cars that nobody wants. For example, parts of Africa have become dumping ground for cast off used clothing donated from affluent countries. The poor can pick off what they want from mountains of clothing. Perhaps we will see giant tracts of land in Africa covered with used vehicle, a defacto pick-and-pull for spare parts. A giant fleet of old ICE could cannibalize through to the next century. This could have adverse environmental consequences for poorer countries with cast off fleets. Proper recycling of used vehicles might not be available at scale in these places. When ICE values decline so much that affluent countries are "donating" ICE to poor countries, watch out. Donating easily crosses the line in to dumping. Dumping ICE into poor countries that lack automotive recycling infrastructure is negligence. It would be far better to recycle cars in affluent countries and donate useful reclaimed metals to developing countries if one has genuine charity in mind.
Of course, in affluent countries there very well may persist a nostalgia market for ICE. But my hunch is that the nostalgia market will fixate around certain iconic models and types of vehicles. Watch what ICE models remain in production the longest. There's a lot of forgettable ICE that will go out of production by the end of the decade. My own modeling suggests that from 2024 to 2030 non-BEV falls from 80% of new car market to 20%. This is a rapid collapse of demand for the most forgettable models of ICE. What's left in production after 2030 is largely niche, nostalgia or going-out-of-business models. Only the nostalgia models will have any sort of durable value. However, nostalgic petrol heads will have a huge supply of used vehicles to pick over for many decades. Nostalgia buyers may even find that they prefer pre-EV vintage model years to post-EV model years. As companies like Hyundai shut down ICE development units the quality of new ICE could decline. ICE makers just try to make the post-EV ICE models as cheap as possible with little inspiration or innovation. So the nostalgic car buyer could come to appreciate the older model years back when car makers still had some passion for antiquated technology.
Another twist here is that if you can use your smartphone to call a self-driving EV at lower cost than owning an EV or ICE, then quite a lot of us could forget even about owning a car. This would be like the digital camera we never use because smartphone.