Why do some say that using anything that holds hair together could damage the hair and cause split ends/breakage? Is this true at all?
Most things you actually do to our hair can potentially damage it.
It is easy to break or damage individual hairs particularly when taking off any kind of pony holder. Also, wearing a holder that is too tight can pull out hairs.
Against that, however, wearing hair tied back can help to prevent it getting tangled, and a lot of damage can be done by brushing or combing long hair if it has got tangled.
With short hair, very little damage can be done as there isn't much to damage. The longer the hair you have, the more care you need to give it by treating it gently and not using actions or tools which are too rough on it.
Be very careful too with any kind of chemical treatment, and always use a good shampoo (not necessarily the most expensive) which you find suits you and your skin type.
Hope this helps
I simply use a hat to hold my hair together (more than anything, the hat keeps it out of my face). From what I've observed, very little (if any) damage is done to my hair at all when I slick it back and use a hat to keep it down (sans gels or any gunk with the potential to damage it). Of course, hats aren't appropriate for just any setting/environment, so on that note, I sympathize with your concern. In such situations, I just let my hair be as it is.
Just make sure you use holders that are relatively soft and do not have any metal parts. Scunci makes some good ones called "Hair Hoisery". Also, make sure that you only put your hair in a holder when it is DRY. Don't make the holder any tighter than you have to. If two times twisting does it, then don't do three.