In such types of gambling as roulette or slots don't have to think at all, and therefore gambler can be in almost any state, either under the influence of alcohol or sober - this will not change the outcome.
But in fact, there is a variable that will certainly change the outcome of the day in which the gambler decided to play, this is the bet and the desire to continue playing. It has been proven that drunk people do not want to stop, the ability to say a strict "stop" to themselves is inherent only to sober people.
And a person under the influence of alcohol will most likely increase the bet uncontrollably.
If someone gambles under the influence of alcohol, it's a matter of who will fall first: the gambler, who can't continue due to the excessive alcohol, or the one who runs out of capital due to uncontrolled gambling. Therefore, even controlled and sober gambling can still result in losses, especially gambling under the influence of alcohol.
This is something to avoid. Drinking alcohol can increase our focus and relaxation, making us calmer when making betting decisions. However, if consumed excessively, the opposite can happen and lead to chaos.
Excessive or too much of every thing is very bad just as you have said and I also have said a couple of times in my previous posts, but let me point out that people are still different though, there are people who would be under the influence of alcohol and still maintain their stability and normal behavior even when they are intoxicated, but this is still not an excuse to drink excessively..
Drinking and gambling both go in hand, this is why can never see a physical casino without bar section or area, this is not bad at all since this is also another business the casino can make money from, but the gamblers should drink moderately if not for any other reason, but for their health and well-being.