I find it useful to have multiple monitors or a large monitor that can support multiple windows comfortably useful for development, e.g. multi-pane IDE, terminals, documentation all visible simultaneously. The distraction problem is that everything else (slack, email, internet) is just a click away. I wonder if the answer is to treat the computer desktop like a real desktop that only supports having the materials open for one task at a time. So consciously switch tasks by putting the old things away and getting out the new things.

Maybe the fact that slack and outlook take a painful amount of time to open is a feature not a bug