Well, not to defend a Man, but John did win the war too. 😛Â
The first terminator was sent back as a last ditch effort AFTER Skynet was already defeated, to prevent a future in which John was born and would lead the resistance to victory. And Dani, I guess does something similar, with the Rev-9 sent back in the same way (all these damn parallels and they think I’m not gonna treat Grace/Dani like Reese/Sarah). In a way, what Sarah did was perhaps the biggest victory of all, putting off the war entirely, and if these movies didn’t have to continue being made, maybe there’s a timeline where she and John are genuinely relaxing and having fun.