In fairness the franchise overall is a bit weird with the seemingly tiered nature of the Saints - Bronze, Silver, Gold and all - versus Cosmo as this will driven force that can be ramped up to overcome the odds. In any other series this would probably mean the Saints being rewarded with higher Cloths as their mastery of Cosmo increased, or otherwise their Cloths 'evolving' with their mastery, but no matter how good the main cast gets and whatever foes they best, they're not readily promoted, and often reset to their nominal place in the hierarchy. Sure, their cloths do get upgraded, but it's external of them and kinda begs the question why the Cloths are even tiered at all if that's possible.
This is admittedly something especially exacerbated by the anime since, being anime and all, it often relies on the assumptions in this status quo.
Edit: Hell, even as someone who likes (the first half of) Omega, this was one of the weirder aspects of the series. Sure, they allowed Seiya and Shiryu to upgrade, but apparently the rest of the veterans weren't allowed to nab any of the Gold Cloths that were given off to what were basically amateurs.