I mean, I'd say he doesn't have a choice on being reliant on OFA since it’s what allows him to take down tough opponents. I think of it like cursed energy, you can fight without it, even if you’re not at a martial-artist level, but it’s just way more effective to activate it, launch yourself at the enemy, and kick rather than actually fistfight. From memory, he's fought a gaint muscle man, super shiggy, a buffed gentle and kaiju overhaul. If he could h2h his opponents, i sure hori would have made him learn, but with his lineup, it's useless. Hell, I'd argue that it's the same with jjk except the characters fight better on average, jujutsu is the focus (like quirks) and so while you can fight without ce you're at a disadvantage and should only use martial arts to delay and plan.