Children are more important than the truth.
Donald Hoffman's argument is precise, evolution does not select organisms for accurate perception of reality; it selects organisms whose perceptions help them survive long enough to reproduce. If a distorted perception leads to better survival outcomes, evolution will keep the distortion.
There is good reason scientists take this idea seriously. Natural selection works on outcomes, not on truth. If an organism behaves in ways that keep it alive and reproducing, its genes persist. Whether its internal model of the world is objectively accurate is secondary. In many cases, simple shortcuts outperform accurate models because they are faster and cheaper. Evolution tends to favor efficiency over truth.
Declining reproduction is interesting nowadays is rather revolution not evlutin. Biological evolution in is slow compared to cultural and technological change. What is changing rapidly is not genes but behavioral strategies and environments. When reproduction declines in certain populations, several things can happen. Some groups continue reproducing more than others, which gradually shifts demographic composition. At the same time, technology, education, economics, and institutions shape behavior much faster than genetic evolution. In other words, the direction humans move next will likely be influenced far more by culture and systems than by biological evolution alone.
However, if the trend continues today it will certainly be a major setback in human evolution.