EW Relic Grind is just a streamlined version of ARR/HW Grind
Older relic grinds involve steps such as doing dungeons, trials and other duties to farm hundreds of thousands of points of "light" or to awaken mahatmas or whatever. These resources are really just thinly veiled: "do this old content repeatedly for a specific resource". What they did in EW is remove the specific restriction of forcing you to repeat the same duties instead to Tomes, which allow for you to do ANY relevant content.
So previously you had to do 60+ Garuda HM to maximize light. Instead of spamming the same duty, you have the freedom to do any duty and the relic just requires the common currency they all award. It's literally the same difference, they are just not pigeon holing you into only doing dungeons and trials and 24mans, which btw were content that already gave tomes. Instead of making a separate light, it's just tomes. You're still doing duties for them, you just get to pick your poison.