It seems that the main and only problem "solved" by SCRUM is the awkward situation where a freelance-team or solo developer happily present the result of their (web-, ux-, app-)implementation that took them half a year, the customer realizes they wanted something else and both are angry at each other.

So now SCRUM has a feedback cycle that prevents that from happening.

It makes sense for UX and interaction-heavy parts, but not at all for systems and backend programming, which are much harder to divide into a workable backlog.