The "new users, who often struggle to find their footing" are going to turn to AI. They already have, hence the drop in traffic.
That's good! (For them.) A personal helpdesk that can walk you through your particular problem, debugging, homework question, etc. That's way better than waiting for humans to try to understand and answer your slapdash question.
So it's really unclear why the company is redesigning the classic Q/A site to be better for those kinds of questions, when AI already exists and is already really good at answering them better and faster than the human volunteers here can.
Stack Overflow Q/A (classic) provides the library of high-quality, curated questions and canonical answers. This will continue to be valuable both for humans and as the training data for AI. Keep it as is. Provide a different path / different website for the helpdesk questions... and you should probably power that with AI.
(N.B. I have a hard time imagining why many people would turn to Stack Overflow's AI agent for help, when ChatGPT or Claude or whatever are probably better for the task and have a brighter future. That sucks for the company; you probably won't have disruptive growth or earn back the $1.8 Billion purchase price. But this redesign isn't going to fight that tide either.)