There is no reason to keep ability scores anymore. Most people who are giving reasons just don't really understand the question. In 1E/2E, there was an enhanced bell curve to abilities that would be harder to represent (in that bonuses were uneven with respect to the score AND the score was generated on a curve). When you roll, the score itself is still generated on a curve, but honestly you might as well just put a table in the book that says "If you roll a 14 or a 15, your ability is +2" and be done with it. If you're doing point buy, it's linear so you don't even need the table. Worse, with point buy people won't even buy odd ability scores so they are really just buying the bonuses anyway.
After creation, the scores are all but meaningless. The only slight meaning is granularity, but that type of information adds nothing to the game. People are just too used to the concept of the scores to easily let them go.