It teaches them accountability and responsibility I am often told.
I disagree, as do many great teams in sports.
How does making someone younger or with less team experience than you carry your stuff teach them accountability? Doesn't that just teach them, that when you're older you don't have to carry as much stuff? And with that, the message, "when you're older on this team you have less responsibility and accountability, because they'll be freshman to help carry your stuff."
Arguably the greatest rugby team in the world, the All Blacks, featured in the book Legacy; have a saying. Sweep the Sheds. The captains are in charge of this. It literally means sweeping the locker room wherever they are. No matter the outcome of the match, the leaders, the captains, ensure everything is orderly. This attention to detail and demonstration of accountability and responsibility is what fosters accountability and responsibility in one of the greatest sports team cultures on the planet.
Making someone else do your work or carry your equipment generally does not send the message intended by tradition. Doing so on the terms of tradition is also stupid. There are countless things we've changed in our country because what we've done in the past no longer is best. The past is a terribly precedent to super-cede rational judgement.
When I joined my college team, they had been 7-4 for three years in a row. Missing the FCS (1-AA) playoffs. Prior to that, seven straight conference titles and playoff appearances. The first day the upperclassman reported to camp that Fall, an all-conference returning DB in my unit came up I kindly informed me I'd be in charge of carrying his playbook and pads after practice. As this happened I realized my two other freshman were receiving the same instructions from other seniors. We obliged, looked at each other and stated we weren't going to make younger guys do that when we could.
As we red-shirted that year, rookie shows and carrying stuff for others were more important that finding the micro improvements to break back into the playoffs. That year the team went 7-4 once again, missing the playoffs.
The next year, we had a new coach, some new staff and our defense chose not to make others carry others crap. Especially a playbook. How are you supposed to learn, if some freshman is carrying your materials? You also trust a newcomer with your playbook more than yourself? With a new coach, breaking of wasted traditions we won conference and made it to the national semi-finals, loosing to eventually National Champ Montana that year.
If you want to teach your underclassman on your team accountability and responsibility, model it. Show it alongside them, not by creating a separation of duties and responsibilities. Teams that everyone carries their own weight, are able to carry more weight. Don't let traditions get in the way of progress.