The metaphysics of Infinitism establishes that there is objective reality. This is the foundation upon which the epistemology of Infinitism rests. Because there an objective reality, it is capable of being perceived and measured, even though it can never be truly known with certainty.
Infinitism also views humanity as extraordinary. Humans are unique on Earth in that they are universal explainers and universal constructors. We have the potential for infinite knowledge and thus have infinite capacity for physical transformations. In this sense, humanity's place in the universe is significant, rather than insignificant.
Infinitism's answer to why the universe exists is somewhat agnostic, but favors the circular argument and the regressive argument over the dogmatic argument of the Agrippan trilemma.