I think this is a rabbit hole that makes you want to pull out of it real fast. For instance consider how many tech jobs right now basically devolve into trying to make people see ads that they don't want to watch. Not only are you not adding value to the world, you're actively making it worse.

Of course people can convince themselves with all sorts of rationalizations, like claiming you're introducing people to things that can make their lives better that they might not have otherwise known about. But that's just a fallacy. Good things, with or without advertising, gradually become known. Online ads are overwhelmingly about shoveling chaff down people's throats.

And poker players have the same sort of rationalizations. You might view oneself as an athlete, or an entertainer, a competitor, or maybe even just an analyst. Many of those descriptors, in my opinion, fall closer to reality than ad delivery rationalizations, but again it's all just rationalizations anyway you look at it.

The number of people working truly valuable jobs that genuinely improve society are few and far between, and they tend to pay terribly. Farmers being a textbook example. There are some good counter-examples like doctors, but even there there's an undesirable trend. Working at a poor public emergency institution is going to drive relatively low income and high stress. Go work as a plastic surgeon in Beverly Hills and you're driving an extremely high income and low stress work. All in all we have a pretty terrible system, but nonetheless it's almost certainly better than all the others.