Maybe at lower levels there are more winners (although nowadays not even that), what happens is that people go up a level and then end up losing.
That's also the tricky part: the professional poker players get all the attention, and anyone who starts playing poker thinks they'll make it there. In reality, most of them will lose, and if they lose to other players that means that loss for them comes on top of the house edge.
And getting to the top is not so pretty. Many go broke even after arriving. I admire Daniel Negreanu because he is a nice guy who knows how to explain very well, does very good analysis and knows how to entertain the fish at the live tables. But look:
Being Broke but Never Quitting: The Years That Built Daniel Negreanu’s Career Negreanu describes going broke numerous times back then
Daniel Negreanu Took it on the Chin in 2023Daniel Negreanu is $2,228,174 in the hole playing tournament poker last year, he said on his annual state of his bankroll report that he’s been doing for several years through his YouTube channel and elsewhere.
At least he was able to pull himself together many times and today he has enough wealth and varied sources of income to sustain a year of losses but there are many who were famous at some point and ended up disappearing either by going broke or by a brutal variance that they could not bear, something that happens especially with players of multi-table tournaments.
It can be said that any activity can bring a good profit. Ok, that's a possibility, but not mandatory.
Ehh no. If we talk about making money on a regular basis, in casino games you can't, due to the House Edge.