Can we assume gravity is weakening instead of accepting the existence of dark energy?

I have been considering an alternative explanation for the observed effects typically attributed to dark energy. Rather than invoking an unknown force driving cosmic acceleration, could these phenomena instead arise from a gradual weakening of gravity over cosmological time? If gravity were to diminish on large scales, how would this reconcile with general relativity, and what observational consequences would it have? Additionally, how would such a hypothesis challenge or refine our current cosmological models?