Relic zenith wasn't that great either, but once you got the ability to customize the stats with sphere scrolls/materia it became much better.
Actually, all the steps for building a zeta were tedious and gil-intensive, specifically to discourage people from blowing through it quickly and getting a free 125 or 135 weapon. It's about as much "effort" as grinding the equivalent raid tier for a drop, so you balance how much time you want to waste on doing lots of easy tasks versus time you want to waste doing fewer harder tasks.