This summary is not the rule. The rule text controls.
Witnesses can give their opinion even if that opinion touches on the exact question the judge or jury has to decide. In the past, some courts blocked this kind of testimony because they said it stepped on the jury's job. This rule gets rid of that old restriction.
For example, in a car accident case, a witness could say they think a driver was going too fast to stop safely, even though "was the driver negligent" is the main question in the case. The opinion just needs to meet the other rules for testimony, like being based on the witness's knowledge or expertise. As long as it passes those other tests, the fact that it deals with the main issue in the case does not make it off limits.
This rule makes trials more practical. Witnesses, especially experts, often have useful opinions that naturally relate to the main questions in a case. Blocking that testimony just because it touches on the ultimate issue would keep out helpful information. The jury still decides what to believe and how much weight to give the opinion. They are not required to accept it just because a witness offered it.
