Old age will make you not enjoy the fun in gambling anymore, because you will not derive pleasure in it. The moment you don't have appetite for gambling, you will not see it entertaining anymore. There are a lot of things that will be put aside at old age, because it's not what you want at that time. However, if you are the type that gambling is your hobby, you can continue gambling when you are old since you are still enjoying it and do it for fun, to keep you away from boredom.
I disagree with you, many older addicted gamblers now began gambling from a younger age and i keep the guess why they never stopped gambling. Gambling is said to be fun, especially those who only are interested into sports betting, as long there is still love for the game of football, i think there is nothing to consume their interests from gambling. The only moment that ease the appetite of gambling is that of responsibilities and after several tragic experiences that got the user really frustrated and decided not to partake any longer but as of getting old and losing interest i doubt such speculation.
Anyone can stop gambling either at a young age or older, it depends on the particular individual and the reasons behind the stop, getting older does not have any influence whether to stop or not, at most old age even increases the appetite to gamble especially if the individual has made a lot of investments that keeps him off jobs and all he does is sit and wait for the steady income, such old gambler will likely enjoy his relaxation by gambling.