I think 90% of peoples issues with window management can be solved by using workspaces intelligently. I won't prescribe a specific method, but I personally keep certain things on certain workspaces. Browser on 1, dev on 2 and 3, chat on 4, music on 5, misc on others. I rarely need to use more than 5. And then I have bindings to go straight to these workspaces(mod-number keys).

My personal hot take is also that most people who think they really need another monitor are just addressing these symptoms because they're exhausted by alt-tabbing through 15 windows. They would be more productive on a single screen with a nice workspace configuration, though there are of course plenty of good reasons to want multiple monitors.