Turf war is literally baby mode, to anyone who isn't Nintendo's target audience I.e. actually wants something competitive it's relegated to the mode you go to to try out weapons and/or go for win streaks
If you really want to be annoying then arguably the first minutes do matter because they let you get information. Turf war is a gamemode carried by one good player so recognising who the threats are and how they might try to push in that last minute is what the first two are for