Looks no older than 2.5 to me in that video. If that was all I had to go on, with looking at the neck and brisket, and other characteristics there is no way I would guess he was any older. He does have a "young" face too.
He could be just big enough to do fatal damage to other bucks. He needs to go.
In 2016, I think, we had a buck with no antlers fighting with and running off 2.5 year old and younger bucks. He was big, guessed him at 3.5. The following year we had what we believe was the same deer with a rack that was shredded by the time the juvenile hunt opened. We saw the deer several times and had hundreds of pics of him. Before he started fighting he was messed up on his right side, but left side was perfect. Then in 2018 thought he was back, but this time his left side was messed up and right side was nice. We couldn't decide if he was the same deer. Both had a notch in the right ear. The deer in 17 developed an access on his right side that we watched grow to the size of a golf ball. It eventually went down by early January. My wife killed the deer in 2018 and his teeth showed he had an abscess right side. We concluded the chances of there being two different deer with these similarities was extremely unlikely and that it had to be the same deer.
My point in that, is that when deer sustain injuries to both the antlers and to their bodies from fighting, their antlers can do some funky stuff. Dr Leonard Lee Rue wrote about contralateral condition from body injuries, and I understood that injuries to antlers could hold memory, but I never would have guessed a deer to have their antler characteristics with messed up to change sides.