The fact the cost of restoration is likely to exceed the final value of the car has been known for a long time.
I am currently restoring a long abandoned project car from piles of parts, its a giant jigsaw puzzle. I am doing all of the work except the final upholstery and with luck I could sell it when it's finished for about what I will have spent on it but even if I end up losing money, so what, I am retired and it is what I enjoy (mostly!) doing every day. it's a hobby where you can recover at least some of your expenses and the result is rewarding.
I could buy the same car in nice running condition and take it for drives but what would I do the rest of the time? The project keeps me busy all of the time, even when I go to bed trying to figure out the solution to a problem. Sounds good to me.