True, it is considered one of the two top honors in Math since last decade. Previously it was the only distinguished prize.

There was a growing need for another award which bridged few gaps. The 40 year cutoff age, awarded every 4 years to living mathematical prodigies failed to honor several prominent mathematical breakthroughs which came after decades of painstaking research.

As the field has progressed, monumental breakthroughs are harder to come by early into career. Many of the ingenuity comes from cross-study of disciplines for e.g. Riemannian hypothesis being approached by Algebraic geometry and Topology rather than number theory. These require years of mastery - not just prodigy. Also the prize money offered by Abel Foundation is a good incentive for research into pure math