Science offers truth to the world, to a certain extent and within certain limits, but science does offer truth. Many persons have little or no confidence in the teaching of the Church on moral truth, and yet they have great confidence in the teachings of science on scientific truth. Even if those scientific truths are not proven, but are accepted theory, they generally accept those ideas as truth.
The Church is guided by God in teaching moral truth. The truths of Sacred Tradition and Sacred Scripture on faith and morals are Divine Revelation. And the teachings of the Magisterium from Tradition and Scripture (and from the natural law) are guided by the Holy Spirit. The teachings of science are not Divine Revelation, nor are scientists guided by God in any extraordinary manner, as is the Magisterium.
Many of the truths taught by science are not obvious truths. For example, quantum mechanics, relativity theory, evolution, and various teachings in the disciplines of physics, chemistry, biology, etc. are not obvious truths. Sometimes the teachings of science on any subject is surprising, even to the researchers proposing a theory or a result. Scientific truth requires study and investigation, and the result is not simplistic or obvious. And it is not unusual for a scientific result to be contrary to the common understanding or expectation of the general population, or even of most other scientists.
And the same is true of morality. Many people hold to a personal ethical system that is very simplistic. Nothing is said to be immoral unless it is obviously immoral, unless it seems immoral at first consideration. Nothing is said to be immoral if most people are in agreement. But why should moral truth be any different from scientific truth in this regard? Many of the truths taught by the Church on morality are not obvious truths. Moral truths are accessible to reason, but this does not imply that they are obvious at first glance. And the reason of fallen human persons living in a sinful secular world is particularly subject to error. So the moral truths of Divine Revelation, taught by the Magisterium, are often surprising, even to the faithful members of the Church. Moral truth is often not the obvious or the expected or the majority opinion.