buying more tickets will give you bigger chance to win the lottery. If you only rely on your luck on this kind of lottery then you should need to be very lucky to win with less ticket. I can say that buying more tickets on lottery game = increase your luck factor. Of course it is still not a guarantee but at least having more chances is better than relying on luck.
Though what you are saying is technically correct, but i think luck doesn't depend on chances. No increment in chances can make you lucky and get your more close to winning, and even if it gets you closer to winning, but still if you lose then that doesn't matter at all. Losing is losing anyway, no matter if you have more chances of winning or less. In gambling, people with luck even win the bets where they set the winning chances at only 1%, and on the other hand, unlucky people lose the bets with 99% chances of winning.