[Discussion]

or the game has a charitable purpose (at least 10% of the winnings go to charity).

This is like the Russian Railways lottery, where conductors try to sell tickets, saying that 10% of each ticket goes to sick children.
Well, the standard answer to this is that it would be better to donate 100% of the lottery ticket price to charity, without involving Russian Railways...

The lottery example clearly shows that gambling does not lead to anything good.

The lottery example doesn't show anything new. It only shows what is already known – that there are people who are mentally unstable.

Gambling can be a very good way to discipline and structure thinking. But there are people for whom it has the opposite effect. But with the same success, many things can be declared harmful in such a situation...

For example, most people who win a large sum of money in the lottery – which is also a form of gambling – end up in a very bad situation (with a rare 1% exception).

Please provide a link to an authoritative statistical source that includes all winnings (not just isolated newspaper cases) and the fates of the winners, statistics for a year, five years, 10 years, 20 years...

gambling violates the principle of truthfulness.

Give a definition of the principle of truthfulness. A fair game, whether it involves money or not, does not violate any principles of truthfulness.