It depends, sorry can be said in different ways, for instance:
Sorry can be said too often, and when it is not needed, for things that are beyond your control. For instance people who say sorry for what other people, with whom they have nothing to do, do. This is a sign of victim mentality, and is not the best behavior, and is passive agressive.
Sorry can be said in an agressive way, to enforce ones opinion in a conversation, as in "Yeah ok, sorry, but..."
But if sorry is said in a sincere and honest way, at the correct moment, and in the correct context, sorry is one of the most strong words that exist. Saying sorry like this shows you accept that you made a mistake, and you own it. You take responsibility for it, and you apologise for it. This allows the other party, the one you say sorry to, to deal with the issue for which you are appologising. You show them that you feel the troubles your actions created for them, you show them that you care.
Saying sorry shows strength, responsibility, and empathy.