No, I didn't miss the point. I just misinterpreted what you said. You are correct that the jackpot will eventually be won. I didn't realize you were referring to multiple drawings.
However, even over multiple drawings, the chance someone will win is actually still less than 100%. The probability gets smaller and smaller as more drawings occur (and a progressively larger number of tickets are purchased each time). And, it eventually gets so close to 100% that it is effectively certain.
I'd have to go back to my statistics textbook to find the actual name of the distribution that describes the phenomena.
A correction: the probability (of a winner) gets larger and larger. I inadvertantly inverted my thinking to the chance that someone will not win (that does indeed get smaller and smaller).
I think the correct description of the phenomena is the binomial distribution. It gets more difficult to compute when you have multiple drawings (with different probabilities for each single drawing), but the concept is the same.