Fishing is mostly an excuse to sit on a boat and drink beer all day (a high quality activity I fully support in moderation)

Car enthusiasts are mostly about making something look cool and have certain stats, it’s about fun not utility.

Cars are about fun but you can learn a vast amount of practical engineering from the process that is applicable in Broad aspects of life.

I won't tell others how to live their lives, but I think this has more value than how to optimally crush candies for example

The hunting and fishing byproduct was only the pretense, it was to spend an afternoon in the woods or on the lake. And the cars weren't exactly practical, they were impractical muscle cars that broke down often and were a mess of upkeep. If we're looking at useful byproducts that tells me factory working is the best past time one can have.

Most people whom I know - do fishing as a hobby in local lake or something similar - actually return the fish to the Pond/Lake after catching it. There is no food to be had from these activities.I am not saying that is what parent's grandad did but just a data point.

Saying that fixing cars or fishing as a hobby "produce useful byproducts" is like saying playing video games and PC tinkering produces useful byproducts of programmers and content creators.

I don't think this is a compelling argument. It's an extremely inefficient way of producing those "useful byproducts". A person fixing and tuning the same old car for years?

the useful byproduct of my interest in computers is that i understand what my kids are doing with the technology and what the technology is doing to them.

I can't tell you how many times historical knowledge from age of empires has come in handy. And I know my way around parts of DC due to fallout.

All 4 examples main benefit is knowledge to be used later.

If the car isn't your daily driver, then working on it is superfluous.

People who fish with a pole rarely catch more than the investment made into their gear and bait.