Will Relics create the same problems that they did in FFXI?

[Orophin]

I think the issue was that the level cap sat at 75 for so long. Had they raised level cap a bit sooner, and added the relic upgrade quest, there would have been no issue.

This is the underlying problem to OPs concerns. At this point, they've introduced relics before they've even done a level cap increase. To make them worthwhile, there needs to be system in place to upgrade the relics when there are level cap increases, else this game is going to turn into WoW (some may argue it already has) with how gear becomes obsolete only after a few months.