Especially in gambling, no one can ever be skillful enough. You may be skillful but you may not be able to change the outcome of the game. Suppose you have been gambling for the past five or ten years but you can never say for sure that you will definitely win or that your chances of winning are 100%. That's why I do not see the assessment of skill being perfect in gambling. They may be able to entice others to gamble but they have not yet found a way to prevent themselves from losing.
You already have this mindset that it's impossible to win in gambling long-term, but I disagree, especially since we're talking about sports betting. I've seen a few successful bettors based on their claims
(though I can't verify them). However, I truly believe that with analytical skills and discipline, long-term profitability is possible. Not winning every time as that's unrealistic, but at least maintaining a positive ROI, which I think most casual gamblers fail to understand.