No, I mean that if you start with "you won't land on any given rational" and sum that up to mean "you land on any rationals", that argument also seems to prove

No, I mean that if you start with "you won't land on any given rational" and sum that up to mean "you land on any rationals", that argument also seems to prove that you can't ever land on any irrationals either, so as an intuitive argument it doesn't really point toward why you'll always land on an irrational and not a rational. ("You'll never land on Pi because the odds of picking out the infinitely many digits is zero"- repeat that for every irrational, and naively sum that up, and it looks like you'll never land on an irrational either, which is not true.)