Sora does have impressive Acrobatics, Teleportation (Via multiple different methods, including often used forms such as Rage and Ultimate Form), can become momentarily Intangible, can use the Honey Pot formchange to literally slow enemies down via a copious amount of Honey (yes I'm serious), even if he's caught and can't escape for whatever reason, he can also Telekinetically manipulate his Keyblade (And even if Kratos grabbed that too, Sora can desummon and resummon it into his hands), and even if Sora starts to get tired, I believe he can renew his stamina via his Cure spells (Other supporters of the verse can feel free to correct me if I'm wrong anywhere), and all of that is WITHOUT the X-Blade, which also allows Sora portal creation if he so chose as a option.
Even if Kratos has experience with some of these, it doesn't inherently negate them being a factor, Sora is simply very difficult to land a hit on as of KH3, and if Kratos isn't trying to be lethal, I imagine Sora will teleport out of any hold Kratos does catch him in before he gets too tired to keep fighting, just to heal himself.
That said I don't know what Sora has that would put Kratos down. I haven't looked too carefully at Kratos's page, but I know he deals with some insane enemies. I do kinda agree with the "they eventually talk it out and sort of become friends" agenda unironically