Saints could get to $14.61 million under the cap without restructuring Derek Carr, after Saints salary cap potentially increases by $5M

You are assuming that 4 players will take pay cuts. And they are just a few of the players that will need to be restructured
I had to restructure or cut 15 players just to get cap compliant with DC being a 6/1 cut , not counting any pay cut TH or Cam would be doing
Try over the cap for yourself

I'm not assuming. I think they likely will but even if they don't I'd rather have those vets that are leaders on the team than Carr. And all of them are still relatively productive players.

And I don't have to look at OTC because several posters here have given more than reasonable options for cutting Carr if that's what Moore wants to do.