The question isn't "is there a vaccine that has no breakthrough cases" but instead the question is a comparison of vaccines and the % of breakthrough cases. Where would the COVID vaccine rank on that list? And if it ranks near the top (and it does, I'm sure) of % of breakthrough cases - then the next question is "does the vaccine pose a risk to those who take it?" And that also is true - there is a risk. So we then compare the risk of taking the COVID vaccine to the risk of taking other vaccines. And again, if it is at the top, then we have a high risk, low efficacy vaccine that is being pushed for a virus that - for the vast majority who get it - doesn't cause danger. So that's the problem.
Let's do a comparison.. Covid vaccines have a vaccinated breakthrough rate of under 0.5% in an environment where the disease is highly prevalent. The vaccines for measles and mumps has a vaccinated breakthrough rate of over 3.0% in an environment where the disease is highly prevalent. Covid vaccines rank very well in the list of vaccinated breakthrough case rates in a population where the disease is highly prevalent.