I was taught at the Infantry School to remove the sling in the field. Snags on everything including the gear I was wearing.
And if you dropped your weapon, you got immediate feedback from Drill Instructors on your error.
Graduates of the Infantry School do not drop their weapons, nor do they need a sling. They don't transition to a pistol or shotgun, the weapon is their primary and only means of defense, so they treat it accordingly. MP's might need to retain it during street detentions, 3Gunners use them in competition.
Infantry just shoot with two hands on the gun at all times. No slings. Don't use them deer hunting on my AR's either. Same problems, snag up on everything and are no help.
You hang up on a combat hatch exit from a M113 and you will wind up with boot marks up your back. No slings.
Exit a Hummer or old school Blazer in the day, door handles and knobs abound. No slings.
Just say no to $50 slings and $60 swivels. HD slings and expensive forged swivels are like using aircraft cable for a dog tag chain.
Not for me.