because you can earn and loss profit at short period of time
not only that. however, gambling was consumed us. time becomes useless because we do gambling.
If you think gambling is just wasting your time means that you do not know how to manage your time, nothing else. So you need to learn how to manage your time on gambling, this is one of the most important parts on how to control yourself on gambling.
Yeah, start managing your time by not gambling. Gambling takes too much time from a person and time is his most valuable asset. So, do not waste you time on gambling because it does not benefit you anything except for a few money here and there. There are things which you can spend your time better like sports or learning trading or enhancing you skills. Those things can be more profitable than gambling.