Gambling is one of these field where most people agree to regulate it, including the gambling companies, and it seems to be working decently well.

For instance mobile game gambling could have been way more rampant and destructive, but we have a decent set of rules and laws to limit the impact.

I can't imagine our society with 0 gambling happening, so if people will find a way anyway, I'd personally prefer it to be on the open, in a mainstream way. Blocking marketing wouldn't work when there are so many different forms of gambling, and obviously it also plays a social stabilizer role so I don't see any serious move to effectively stop people from gambling succeeding.

Not the easiest one to make absolute decisions over. National lotteries fund a lot of useful stuff.

National lotteries allow lower taxes, that is all. The same dollars could be raised by taxing people in a progressive way instead of via addictive gambling.

Gambling can ruin people's lives. The government shouldn't support it being easily accessible. It should be reserved for a desert city almost no one lives in on vacation.

I'm glad you brought the inconvenient truth up. Both the lottery and cigarette taxes are used to fund essential programs (schools, police, fire departments) guilt-free here in the states. If those were to be removed, we would be forced to hold a difficult conversation about taxation and how we would fund things from then on.

Although those things could be funded by something else instead (e.g. income or excise taxes)