What you say about our simultaneous preoccupation with death and avoidance of it is profoundly true. I think it’s a fundamental characteristic of our fallen human nature, and a major reason that the Ars moriendi is relevant in any era. At a minimum, the Ars moriendi can provide a helpful reference for people who have arrived at a crisis point—a serious illness in a loved one, for instance—and understandably find themselves unable to navigate it well through the lens of faith. Family members and friends generally want to be as supportive as possible, but they are often unaware of what they can do, as well as the abundant resources available in the Church to help people prepare for death. The Ars moriendi is meant to help in precisely that way.
That being said, I cannot emphasize enough how important it is for us in our daily lives as Catholics to lean into the reality of death, in light of Christ and the Church, rather than avoiding it. Our natural instincts fail us in this regard, because they incline us to withdraw from death and to cling to transient, worldly pursuits. The Ars moriendi makes a careful study of this in its main section, which features a series of temptations from the devil and inspirations from an angel.