I know its a tired troupe especially for comics fans now. Let's look at it On a case by case basis, this clark so far is introverted. He doesn't seem to have much contacts other than perry, jenny, lois, ma, pete and lana. That's like 6 people. His whole reasoning in bvs for keeping on fighting was his love for lois made him realise that there is something worth fighting for in this world. That he shouldn't just give up.
Now, we need to see superman do good without that reason. We need superman to feel that lose and resist the anti life equation . That might be what snyder is going for. I don't know. This could be my speculation/prediction of what might happen.until its done,its up in the air.Also, a similar arc was also part of superman tas.
As for him winning the fight. He might. But, i do believe cyborg and the jl team is able to minimise the collateral due to Clark's unconcious action. Honestly, that's what it's about. "you can't save the world alone". Clark couldn't contain the black Zero event and zod because he was alone fighting an army of gods. He needed focus on zod. Otherwise, clark might save one only to realise zod killed a hundreds more. On top of that, clark is guy with superstrength with human sins like anger. Ofcourse, it can get destructive.