a chicken and egg situation

a situation in which one finds it impossible to determine which one of two things is responsible for the occurrence of another or existed before the other one did

The idiom "a chicken and egg situation" is used to describe a scenario where it is challenging to determine which event or circumstance is the cause and which is the effect, much like the classic question of which came first, the chicken or the egg. The exact origin of this idiom is not documented, but it represents a puzzling situation in which it is difficult to establish a clear sequence of events or causality.

You need experience to get a job, but you need a job to get experience.It's a chicken and egg situation.
Their constant arguing over who should apologize first created a real chicken and egg situation in their relationship.
In the debate about whether technology shapes society or society shapes technology, it's a classic chicken and egg situation.
The researchers couldn't determine whether stress caused the health issues or if the health issues led to stress; it was a real chicken and egg problem.
When discussing climate change and its impact on wildlife, it's often a chicken and egg situation to establish which came first.