What is most likely the reason ostriches and penguins do not have the gift of flight?

Ostriches and penguins lack the ability to fly primarily due to evolutionary adaptations suited to their environments. Ostriches have evolved to be large, Flightless Birds that are Excellent runners, allowing them to escape predators on land. Penguins, on the other hand, have adapted to an aquatic lifestyle, developing strong wings that function as flippers for swimming rather than flying. These adaptations have made flight unnecessary and even disadvantageous for their survival.