My point is that "success" on the stock market isn't always a function of doing anything useful in the real world.

This is true and not just true of the stock market. It's true of the economy as a whole. The stock market is just a manifestation of a specific part of the economy.

If inflation is low you can do the dumbest things imaginable and as long as you make your money back you can keep doing the dumb thing over and over again.

If there was decent inflation you would have to have at least some expectation of a future gain because inflation and by extension the increased interest rates would cause your net 0 investments to be a net loss.

My succeed was meant for the companies not the traders. A trader can succeed by being a parassite on the market, a company succeed by doing stuff. Whether there is more/too much parassitism is something I don't know.

the stock market is doing something useful in the real world.

the aggregate success thrown off by the stock market is a measure of the usefulness of the stock market.

participating in that is what enables to stock market to provide its usefulness.

so, yes, success on the stock market is a function of usefulness in the real world.

This is sort of circular, the stock market can also devolve is pure speculation and go full casino, which are generally considered an example of a not-necessarily-net-positive addition to society.

it's not circular, but more to the point, you suggesting that the stock market can devolve (fail) is like saying "brakes on a car can fail, so brakes are stupid." Brakes are not stupid.

I did not say that, I said that just because the people working with stock are getting paid does not mean that the stock market is doing something useful. Parassitism also exists in free markets.

Stretching the brake analogy it would be similar to noting that just because you are pressing more your brake pedal it does not mean that your car is slowing down faster, sometimes you need an ABS