Superman wins
He has the experience that Steve does not have. You ca give Steve Superman Powers it doesn’t mean he is Superman’s equal. This is why Superman tends to defeat his supposed “equals” like Zod. Superman has used his powers all his life, he has the experience that you can’t just imbue to others by granting them his powers
If you’re trying to give Steve Superman’s powers, knowledge, and experience, then you’re practically making this a Superman vs Superman (+Steve’s experience).
Anyone else trying to argue otherwise is just being biased.