Yes, I still have the M3 which is now 21 years old!
We got an Aygo for Leo's lessons. I don't think the insurers would be very happy if we asked them to insure a learner on the M3. And I don't think I'd be happy with all that maneuvering practice.
Honestly it was terrifying in the earliest days, we have narrow country roads around here and apparently it's not quite as simple as it seems, to time that slowing down and tucking in to allow the oncoming cars to get past, and to steer good lines for visibility and avoid the pot holes, adjust speeds frequently for all the different situations. It's amazing how much there is to learn, to really become competent and safe.
It seemed expensive to buy the car (we were surprised by the price of used cars) but we found a good Aygo and it was nice to combine the purposes of driver training and visiting places for family walks and other activities. The price is comparable to hiring an instructor, but this way he could get more experience before taking the test, and also we still have the car when I'll start to do the same for Nicole in another year from now! We also visited Salisbury and Yeovil several times for specific training in larger towns. As he is now 18 and could leave home any time, this was one thing I wanted to do for him, as it is likely to be useful at times in his life. After 120 hours of driving, including 3 hours with professional instructors, he passed the test first time.
To answer your question, I am very happy with people having a car as an enthusiast. I'm not sure about investment as a rusting investment is a troublesome investment but if people want to do that then that is fine. I am always impressed to see old cars driving around.
The thing I have a problem with, and I've said this so many years ago, when traffic was a bit less than it is now, is the
excessive use of cars. If an alien came to earth and saw a traffic jam, it would have to conclude we were not an intelligent species.
If you look objectively, a huge traffic jam in London or the M25 (circular motorway around London) that recurs every day is proof that humans aren't able to cooperate in a sensible way. The way we coordinate, almost entirely through market forces and transactions between individuals, leads to such absurd inefficiency and pollution, we really have lost our way. So many people having to live so far from where they work, in often 'pointless' jobs that don't really make anything (big subject, won't go there) and having to sit in congested traffic to get there and home again, every day. Less congested, cleaner, quieter and safer cities could only be a good thing, I believe.