I mean...they can, you just refresh the motor. Tons of ICE vehicles out there with 400-500k miles on them. Hell most semi trucks have millions of miles on them.
A rebuild every x00,000 miles on a Toyota sounds nicer than paying the price of a new pilot every 100,000 miles tbh. Computers don't last though and emissions have made it a huge pain to fix on older cars. Nothing against emissions it's a necessary evil.
If they're easy enough to work on, and the parts market is maintained, yes.
Nothing lasts forever without something going wrong, but we can make it easier to fix. It's a little more true of EVs, because they're mechanically simpler than ICE cars. You added an electric motor (which lasts forever if designed well), batteries (life dependent on the chemistry involved), and some electronics to drive that (caps in there go bad, much of the rest will last forever if not abused). You took away an ICE, an intake system, an exhaust system, perhaps some forced induction, a coolant system (which you might have on EVs, but not to the same level), an ignition system, a shitload of sensors (O2 sensors having particularly short life, relatively speaking), and a fuel pump.
If designed to be worked on, the EV is far, far easier.
I am thinking of doing that when my civic should be legally declared dead. With the insanity that is new car prices and insurance for new cars plus the vanished used car market it just isn't worth it. I want an EV but things have to go back to normal before that happens