What crucial factor determines whether Jupiter's influence is deemed beneficial or detrimental across cosmic time?

Timing—its role in initiation versus its role in long-term survival.

The debate surrounding Jupiter's necessity revolves around the concept of timing, highlighting its dual mandate across cosmic history. In the very early stages of the solar system, its role as an inward-deflecting agent was highly beneficial, possibly essential, as it delivered the water and organic materials needed to initiate life (initiation phase). However, once life is established and evolves towards complexity, the priority shifts toward protection against existential threats. During this later phase, Jupiter's role as a shield, reducing the frequency of extinction-level impacts, becomes the critical factor for long-term survival. Therefore, whether Jupiter is judged as necessary depends entirely on whether the focus is on starting life or ensuring its continuation over billions of years.