Video games can be fun but without having money on the line the excitement just isn't there. Most people gamble because of the adrenaline rush that comes with winning large amounts of money. But I guess you could combine both worlds and bet others on video games or bet on professional e-sport matches.
I agree, it's like playing poker, and without money, it's just plain 'ol playing card games, and that's just it. It can be a practice, but with money on the line, you would have more effort in thinking the strategy you are going to employ. The adrenaline comes rushing through the veins and feeling of the veins popping in your head, that's where the improvement comes from, where it's competitive plays.
People gamble not just for entertainment because of the chance to win big money. It is entertaining because it gives you excitement even if you lose in the end.
I don't think losing, in the end, is enjoyable. It's just plain losing and nobody wants that in my opinion. Are you like that? I think people should just prepare with what you are going to gamble with, the amount you are comfortable losing, and just play. Losing still hurts no matter you accept it or not.