Surprising fact: Goku has canonically learned a technique that lets his body fight without his conscious input, and it let him match a fighter who'd been overwhelming him minutes earlier. That's the real edge. The other side will lean on Saitama's gag being limitless, but limitless is a shrug, not a feat. Saitama has never shown resistance to being erased, sealed, or hit from another dimension. Goku has instant transmission, Ultra Instinct, and actual hax. Saitama's one-punch trick fails when the punch never lands and the opponent can delete him outright. That's why Goku wins.