Goku defeats Saitama because his baseline power scales to a universal and multiversal level, completely eclipsing Saitama’s peak multi-galaxy feats shown against Cosmic Garou. Early in Dragon Ball Super, Goku’s clashes threatened to destroy an entire macrocosm containing multiple spacetime dimensions, giving him a massive tier advantage that Saitama's linear physical durability cannot withstand. Additionally, Goku possesses immeasurable combat speed, the ability to teleport instantly, and Ultra Instinct—a state allowing his body to dodge and counter attacks automatically without thought. While Saitama can grow exponentially during a prolonged fight, Goku's initial attack potency is so overwhelmingly superior that he can end the battle instantly before Saitama has any chance to adapt or bridge the massive power gap.

Your argument falls apart because it relies on the "No Limits Fallacy" and misinterprets how both characters actually function based on canon feats. First, One-Punch Man Chapter 167 objectively disproved the myth that Saitama has infinite power on command; the manga features a literal mathematical graph showing that you possess an exponential growth rate triggered by intense emotion, meaning you have a measurable, limited baseline at any given microsecond. Second, Goku does not need a slow "ramp-up" period; he can instantly enter his God forms and possesses immeasurable combat speed, meaning he operates at peak lethality from the very first frame of the fight. Finally, because cross-universe debates rely on actual feats rather than narrative parody, Goku wins "easily" because his baseline universal-shattering strike potency vastly exceeds your peak multi-galaxy durability. Goku quite literally possesses the instant speed and raw, macrocosmic power to completely vaporize you on count one, long before your growth mechanism ever has the chance to trigger and bridge the multiversal gap.

Your argument relies entirely on a fundamental misunderstanding of how Goku’s power works and a misinterpretation of Saitama's adaptation mechanic. First, Goku does not need a "sequence" to access his full power; he has repeatedly bypassed transformations to unleash maximum energy instantly from base form when necessary. Second, you claim Saitama's power "rewrites the rules," but against Cosmic Garou, the manga explicitly stated his growth was a reaction to Garou matching his power, meaning Saitama requires a mechanical cause-and-effect trigger to scale up. He cannot adapt to a threat that instantly obliterates him. Goku's baseline punch shockwaves threaten an entire multi-layered macrocosm—a feat infinitely above Saitama’s peak multi-galaxy durability. Because Goku possesses immeasurable combat speed, his very first strike lands within zero seconds, delivering a casual, universal-shattering blow that vastly exceeds Saitama's durability before his exponential growth loop can even register a threat. Goku wins "easily" because he operates on a completely higher dimensional tier of power, rendering Saitama's growth mechanic entirely irrelevant.