Tower Ending Johnnys line question

Maybe it’s because I finished the game a while ago or maybe I’m just slow, but can anyone explain the line “Good night, Vincent. Today was a good day.”? I didn’t get the super good relationship with Johnny, so I remember him mostly being mad at me when I did the Tower ending.

I saw a yt shorts video where someone showed their favorite “peak” moments in fiction, and that line was included. I went back to watch the scene, but I still don’t really understand it, the scene overall is good as every scene in that ending but i don't undertand what the peak really is, is it Johnny being happy for V? Is that it, or is there a deeper meaning that I’m missing? That's cool don't misunderstand me but i just keep thinking im missing something, Maybe im overcomplicating idk