you don't "help" a company or technology by buying their stock since the said stock is owned by some other dude and the sale does not bring a single more dollar to the company
This is not quite true. Most companies dilute their stock regularly, to compensate management and founders with stock or option grants.
The collection of buyers of those shares set the price for the stock -- which is ultimately being used to provide the company's equity financing.
Now it's true if you bought a share of stock for $1000.... well it's not $1000 that goes directly or indirectly to the company.
But you are trading places with someone who ultimately up the chain bought into their offering.
In the event the buying volume ran out... the stock price could easily fall by a few %. Even a $0.01 price decrease is significant.
So it's not that you aren' "giving" to the company --- it's just that the relative proportions of what you are giving are probably very very small, for a multi-billion$$ company.