Enclave posted... Saitama wasn't up against god though and thus his power didn't need to be powerful enough to overcome them. When he faces them then you'll find he'll be more than strong enough because that's the joke.
I get it, some of you will never accept this and that's fine. Just don't be surprised when this is exactly how it plays out for the rest of the manga just like it has for all the manga before now.
At this point this can apply to literally any shonen protagonist so Saitama isn't special in that regard. Goku will also pull out whatever BS powerup he needs to in order to triumph over whatever OP villain he's facing. Luffy, Deku, whatever. Saitama already lost
to Garou narratively when he failed to stop him from killing everyone he knew, when he admits to Garou that he's a terrible hero, when he needs Garou to teach him how to time travel to reverse the deaths he failed to prevent. Yeah, Saitama will beat God but it's definitely going to have some serious shonen drama and power scaling behind it rather than it just being some looney tunes gag about how all his opponents simply never having remotely been at his level like with Boros and WC Garou.