Skill wise, lacrosse all year has its advantages

Athletically, lacrosse all year is fine (especially supplemented with the right strength and conditioning program)

Mentally, there are toughness attributes that a typical prep school, travel club kid does not have and will not gain on the lacrosse field. This is the differentiating factor for a multisport athlete. Football, Wrestling, Hockey and Basketball offer this (preferred sports in that order)

Football is 95% practice and only 5% games. Mostly pain, limited gain.