This sort of thing and people thinking it probably explains the superman book sales this last few decades. Probably explains the movies inability to connect with audiences over the years as well. Even marvel's smart enough not to let their own boy scout be such a thing. It's not conducive to engaging/relatable characterization.
Secondly, not having superman be the god that can figure his way out of any situation, regardless of how impossible it is, hardly turns him into wonderwoman(the walking Greek myth, blood soaked killer and warrior princess turned peace ambassador), nor does it make her existence obsolete for she doesn't exist to simply fill a singular role in the universe opposite superman, she exists to tell her own stories.
Superman begged zod at the very end no to let it come to that, he then broke down and cried after the fact. If you think that's wonder woman ver.2 you're kidding yourself.
Turns her into a bikini model
How you write superman turns her into a bikini model...
Let's say they don't want to set up a Kingdom Come like story. Problem solved.
But If I may entertain that premise. Coming out of this ordeal it's very likely superman will be bound to never take another life and with a clear motivation, as is the trope. How that
doesn't play exactlly into your little Kindomcome scenario is beyond...I say that cause that's kinda the exact way it happened in KC.