More customization. Most players that are max light are usually wearing Raid or Trials gear. Not much diversity. So bringing back Etheric light would really increase diversity and let people that want their favourite gear to max level without worrying about sacrificing high end gear that you worked for but it doesn't look good to you. For example, I hate the Titan raid helmet, looks terrible to me. But I'm wearing it for the light level. I felt the same for pieces of the Titan armor in CE raid, Didn't really hit off too well with me.