For decades, microscopic consistency in field theory has been implicitly associated with vacuum instantaneity and infinite response capacity. However, these assumptions are not physically demonstrated properties, but mathematical idealizations that introduce an unrecognized singularity at the core of fundamental physics, historically driving theory toward increasingly complex ontologies without genuine dynamical necessity. This work demonstrates that microscopic consistency, causality, and ultraviolet stability do not require an ontology of extended objects. By recognizing finite vacuum capacity as an intrinsic physical property, instantaneity ceases to be a necessary axiom, while field theory remains mathematically consistent in the microscopic regime. The resulting dynamics is governed by a single dimensionless excitation variable, exhibits strictly subluminal propagation, global stability, and uniqueness of the Cauchy problem. By bounding the kinetic response, ultraviolet divergences are eliminated at their origin, showing that UV consistency does not force any specific ontology: a local, strictly four-dimensional formulation without additional degrees of freedom is physically admissible. From microscopic fluctuations to galactic scales, a common dynamical structure emerges as sufficient to describe physical reality. Note: Elements of the underlying theoretical framework are protected by a patent application filed with the Instituto Nacional de la Propiedad Industrial (INPI, Argentina), currently in process. This publication addresses exclusively the microscopic regime and does not disclose technical implementations or operational applications.