In the Marvel Cinematic Universe (MCU), the Eternals are a group of immortal beings with superhuman abilities created by the Celestials, who have lived on Earth for thousands of years. They have been depicted as observing humanity’s evolution from a distance and generally avoiding interfering with human affairs. As such, many fans have been left wondering why they did not intervene when Thanos threatened to wipe out half the universe in Avengers: Infinity War.

One possible explanation for the Eternals’ lack of intervention in the Infinity War conflict is that they were following the rules set by the Celestials, who created them. In the comics, the Celestials established rules for the Eternals, stating that they should not interfere in human affairs unless it was absolutely necessary. This could explain why the Eternals did not intervene when Thanos began his campaign to collect the Infinity Stones and wipe out half the universe.
Another possibility is that the Eternals simply did not view Thanos as enough of a threat to warrant their intervention. Throughout the MCU, the Eternals have been portrayed as taking a long-term view of humanity’s evolution and development, and as such, they may have believed that Thanos’ actions were simply a temporary setback for humanity’s growth.
It is also possible that the Eternals were not aware of Thanos’ plan until it was too late. In the comics, the Eternals are often depicted as being disconnected from the rest of humanity and not closely monitoring human affairs. It is possible that they were unaware of Thanos’ activities until it was too late to intervene.
Additionally, it is worth noting that the Eternals’ abilities and powers are not fully understood at this time. It is possible that they have limitations or restrictions that prevent them from intervening in certain situations, or that their abilities simply do not extend to matters such as the Infinity Stones.
Overall, there are several possible explanations for the Eternals’ lack of intervention in the events of Infinity War. Whether it was due to following the rules set by the Celestials, not viewing Thanos as a significant enough threat, or simply not being aware of the situation, it is clear that the Eternals chose not to get involved in the conflict. However, with the upcoming release of the Eternals movie in the MCU, it is possible that we will learn more about their motivations and reasons for not intervening.