Aren't the casinos already taxed? As far as I know, all casinos have to pay a tax. Even crypto casinos, if they touch fiat, they will have to pay tax. And at least over here, if you play on a casino and win, you have to pay tax on your winnings. It's probably considered as an income tax (not sure about this though). I doubt there are any country out there that doesn't tax their casino. To answer your question, yes tax does help a country. Doesn't matter where the tax comes from, but it helps a country to develop and is one of the main sources of revenue for the government.
The thing is, in many countries gambling isn't legalized, so they run underground casinos and, naturally, they aren't taxed.
And about the type of taxation - it largely depends on governmental policies. All of the countries that allow gambling require income taxes in different ranges (10-30%), some countries have additional gambling tax, related to the type of business you are running.
And some (but not all) require winning tax. There are also policies that dictate different taxes depending on the amount of income the casino receives, as well as on the amount of winnings (e.g. if your winnings are lower than a certain established sum, you may be required to pay only fiat tax).