I think you are drawing a distinction between games where the odds are constant and built into the game, (eg roulette), and games where there is a degree of ski

I think you are drawing a distinction between games where the odds are constant and built into the game, (eg roulette), and games where there is a degree of skill involved but still an element of chance, eg. sports betting where a person with extraordinary insight or privileged information will win more often in the long run than a person who just bets on their favorite team every Sunday. Arguably stock trading and poker fall into this same category. For some people though this is just plain betting. They don't have a strategy or an angle, they just believe they might get lucky and for these people this form of behavior equates games with skill to rote gambling.