You're not entirely wrong. Aviation is a hobby that is difficult to engage in if you don't have money. But flying those same planes is exactly where your commercial pilots are trained. It takes 1500 flight hours (certainly this number is wrong but too lazy to look up the current ATP minimum) to be eligible for the license to fly passengers on commercial airlines. A substation portion of those hours are as paid instructors.

Interesting. So basically the large airlines are skirting the poisoning issue by essentially passing it off to tiny training companies? Kind of like how we "recycle" our electronics by shipping them to a poor country.

Small single engine planes == hobby? No. The vast majority of the hours flown in these planes are for commercial purposes. If you are going to focus your ire anywhere - it should be on these money making enterprises that don't (have to) upgrade their infrastructure.

The negative externalities of your passions, your work, your hobbies, your personal life are currently poisoning thousands of people. You are currently typing on a computer built with rare earth elements mined in poor countries with slave labor. You probably eat shrimp on occasion, literally harvested by people forced into literal slavery, trapped on a boat. You likely enjoy looking at and thinking about crypto, which is currently mined with massive amounts of compute powered by coal plants, which emit far more toxic byproducts than any amount of general aviation.

No one is a saint. Regulating away all the hobbies out there to minimize the impact would probably result in some sort of violent revolution, if it could even be done.

I get your point and mostly agree. However you would struggle heavily to find even one thing that 99.999% of people do that remotely compares to literally flying in the air spraying lead poison over hundreds of miles and thousands or tens of thousands of people, animals, plants that are in your way.

Its like saying lets just make all bombs nuclear cause they kill people either way. One of these things is much, much worse and can be addressed but of course will not 100% solve the problem.

How is avgas poisoning people?

via the leaded gasoline it uses. Same as how leaded gasoline in cars poisoned people. Same premise, different vehicle.

From the exhaust or skin contact?

Both. Though I am not sure but I think you have to ingest it but having it invisibly sprayed all over your skin makes that very much likely.

Thank you.

I myself enjoy hunting humans, as they are the most dangerous of game. Yet I am constantly accosted at my dinner parties, it’s truly intolerable. I don’t see where these people get the nerve to act so holier than thou. We all have our vices.

(/s, obviously)

My gardening hobby does not involve poisoning my neighbour's children. Might be a tad different, pal.