As the title asks, why do some players switch between their melee weapons and their guns when it isn't necessary and if anything could be harmful to them because they'd have to play the equip animations?

I am sorry if this doesn’t belong here, and if I doesn’t I will delete. So I am silver. My team is nice and we are using comms, but the enemy team is crushing us. We are ascent defending by the way. They got the score to 0-7. By this point...