Good: Gives value to exploration. Can add abilities via artifacts over the seasons. Gives more complete customization. If something is broken in pvp (which it CAN be designed for) then they can take it out and rebalance it without having to tune the whole subclass. If something is garbage in pve they can individually tune it. Bad: Can be tedious and it can require things like raid exploration. Can be used to take away abilities via sunsetting. No guarantee of synergy or actual value (the ice rift is basically just vesper radius). There are probably a couple more for both good and bad so don't take what I say as truth but the general idea leads to some good things to come as well as bad. I've got to say I'm now interested at least.
If they are fixed drops or easy to get it'll be great. If they are rng I could easily say " must have x and y augment for raid, must have z fragment to be good in PvP" It would suck not being able to lfg or compete properly due to bad rng drops.