I can't agree more. Sure, there are legit uses for a huge screen (displaying several windows at the same time), but the developer need to focus, focus , focus.
Nothing can break focus more for me than constantly having to switch between windows (e.g.: vscode / chrome).
2 monitors are the way to go for me.
Yes, there are many cases where a lot of space is needed. Like three-way merge ideally needs triple the width of normal code. There are many other use cases - keeping the jenkins build in peripheral vision, having terminal open with running logs, having browser open containing reference / documentation etc. Switching windows is a productivity killer.
For me it's ultrawide. I'm using a 34" display at 3440x1440. I can have two "full size" windows side-by-side. (Full size meaning they each feel about as large as they did on my 15" MacBook display).
3 work the best for me. Debugging an API on monitor 1, VSCode on monitor 2, browser with the frontend rendered on 3. I could also use a 4th for the browser dev console. (Full stack development)