"will not last forever" doesn't comport with observed reality to date. There are literally model A's still on the road. Barring true oddities there doesn't appear to be a model of production vehicle that has gone extinct at any point in automotive history. Anyway, three of my cars are older than I am, and I am not a young man. Buying into their shit is optional.

I meant to say their availability will not last forever.

Finding parts for older cars is a very real concern, aside from a handful of cars that are very popular with enthusiasts.

So pick a vehicle you can get parts for if you're worried, you've literally highlighted the solution to the problem you're claiming exists.