https://www.guildwars2.com/en/news/relics-bring-new-equipment-to-guild-wars-2-secrets-of-the-obscure/
Learn all about the expansion's newest equipment slot.
The GW1 system was still very different from what you described. You could spend points on skill groups, rather than increasing raw damage or crit chance.
GW1 had way fewer attributes to spend points on, but if you did, you would increase the damage and crit chance of certain weapons or the power (damage, healing, duration, ...) of certain abilities. What I was mainly referring to (and what I would like in GW2, too) was the principle of freely spending a budget (with increasing cost) on attributes which improve certain offensive or defensive abilities. Anytime you want outside of combat.
GW1 also has/had Runes and Insignias which require(d) (perfect) salavage kits to move around and hence are/were less flexible. But this has/had less impact on your build than the distribution of attribute points.
Originally GW2's trait system also had stat increases baked in, but this was later removed and more attributes (precision, ferocity, concentration, expertise) have been added.
So why not replace Stat Sets, Runes and Sigils as they are now with freely distributable attribute points and let Relics and whatever the successor of Sigils will be have unique (not stat-related) effects?
I get your point, but this would be a to drastic change for a core mechanic, that is tied to so many other things. How do other stat bonuses affect this? How are base values designed? Are there different scalings for the different classes? What is the use of legendaries if stats are freely selectable?Gw2 is a pretty old game and I'd rather not change the way stats work as a base concept.
A different game (like a successor) could definitely try different concepts, like you mentioned. Just like gw2 is different from gw1.
Another thing I like about the current stat system is the simplicity (even though it is complicated by runes). The fixed stat combinations totally remove that part from the theorycrafting and make gearing much easier. Get Berserkers gear and you can play almost every power build. Get Vipers and you play condi. No need to get that specific item from this one boss, that is only used by reapers.
Your system reduces the need to grind gear (can be good), but increases complexity to find optimal stat combinations.