I really enjoy the "relics aren't for everyone" argument.

I also really enjoyed when people in XI cried when relics became for everyone, or other weapons outperformed relics and still do.

If skill is a deciding factor to obtaining an item, then that is absolutely okay if some players have no chance of ever obtaining the item.

If the deciding factor is an ability to acquire gil or materia, then you're looking at the acquisition of relics from a time spent playing perspective.

WoW handles content extension via 1 week timers on raids (though they have good drop rates); if the issue is making sure the content has longevity, I much prefer having to simply wait to acquire the items I want than spend hours grinding enough gil to maybe get lucky with a meld. The double meld process could be dropped entirely and the quest wouldn't suffer. People still wouldn't beat Ifrit Extreme or 17m AV/CC. You could even stipulate that some master craftsman requires the base weapon and 2 perfect TIV materia where he will painstakingly require 2 weeks to meld for you. You've still had to farm materia/put some gil down for your weapon, but the quest is no longer cockblocking you by saying "Play more hours each day, get more gil, hope you get lucky".

The Hamlet grind is okay, though it could use some retooling as it is still an RNG system.