Nature doesn't "prefer" anything in the way we think of preference. It's more accurate to say that cross-pollination is evolutionarily advantageous for many species. This means that plants that can cross-pollinate tend to be more successful at surviving and reproducing, which leads to them becoming more common over time.

Here are some of the key benefits of cross-pollination:

* Increased Genetic Diversity: Cross-pollination combines the genetic material of two different parent plants, creating offspring with a broader range of genes. This diversity makes the offspring more resilient to diseases, pests, and environmental changes.

* Improved Adaptability: Genetic diversity allows plants to adapt more quickly to changing conditions. This is crucial for surviving in an ever-changing environment.

* Enhanced Vigor: Cross-pollinated offspring often display hybrid vigor, which means they are stronger, healthier, and more productive than their parent plants.

* Reduced Inbreeding Depression: Self-pollination, where pollen from a plant fertilizes its own ovules, can lead to inbreeding depression. This reduces fertility and weakens the offspring. Cross-pollination avoids this issue.

Of course, there are also some species that rely on self-pollination. These species often live in environments where pollinators are scarce, and self-pollination ensures that they can still reproduce.

Overall, the advantage of cross-pollination lies in its ability to promote genetic diversity, making plants better equipped to survive and thrive in a constantly changing world.