Half of the engagements abuse movement
Been playing this game for a while (rank 60), and in my experience about half of the engagements, at least in CQC, involve some form a movement abuse. Slide shooting, jump shooting, crouch spam shooting, etc. It looks whacky, and I suspect that the movement tech takes advantage of the desync in the game, which is its own problem.
Poor positioning, disadvantageous weapon ranges or otherwise unfavorable engagements are negated by abusing movement. It places a disadvantage on players taking a more team-oriented, methodological approach to engaging the enemy. Taking the time to throw a stun grenade before clearing a room, or pulling out the sledgehammer to create an new opening, leaves you momentarily vulnerable, while quickly sliding through the door and catching the opponent unawares will do the trick. It is clearly an effective tactic, or otherwise it wouldn't be so prevalent. Nobody expects battlefield to play as a mil-sim, but currently the game weighs too much on the side of too much movement.