Trading is much better than gambling. Because you can lose a lot of money with gambling and that is all wasted and so bad.
But with trading you have it under control so you can know when to stop or just going further. You have also a higher chance to make some profit.
But do you ever think that you can really earn a lot through gambling? I guess you can earn tons of bitcoin if you are lucky enough and hit some jackpot. Many people prefer trading because is is safer than gambling but compare to their profit gambling is have more payout rather than on trading