One concern I have is that the makers obviously focus all their R&D and marketing on when the cars are new, but that doesn't really help people at my end of the market who buy cars when they're 8-10 years old.
Most if not all batteries are warranted for 8 years. Mine is 5 years old and I've noticed no degradation at all, simply because the software restricts the maximum charge to less than 100% to preserve longevity. Some Tesla's have already done 200k miles and are still above the warranted performance requirements.
You might be right about the efficiency of the ICE but it's not always the case and a 3 year warranty says it all. Typically it's everything else that causes problems for the car, which is why manufacturers make so much money on aftersales.
The thing with an EV is you can run a diagnostic on the battery before you buy an 8-10 year old car and it will tell you in black and white how it's doing.
It's still impossible to do that for an 8-10 year ICE and it's still a complete lottery whether your new, used car will dump oil on your drive, need a new clutch in 100 miles etc etc.
The last 10+ year old used car I bought had the usual checks done, been fully serviced and the engine management light came on after 300 miles. There was no way of telling that a £1000 bill was round the corner.
I'd take the visibility of a battery any day.