One of the largest frustration points since Legion is the amount of RNG that was introduced into gear progression. From War- and Titanforging to Weekly boxes to Legiondaries to crafted items having random stats, and so on, and so forth. Some of these have been remedied over time, but there are still a lot of bad apples in the current system.
- No Justice / Valor vendors, Conquest cap not scaling with CR in favor of the Weekly box
Before we had the weekly box, on the PvE end of things, you could get emblems from just doing PvE, or Justice / Valor during and after Cataclysm, and for PvP, you could get more arena points or conquest points the higher your CR was at the end of the week.
The reason why this gearing system was much more appreciated is because PvEers didn’t feel like RNG was holding their progression back, while PvP players could gear at a natural pace without any RNG involved, while higher rated players could get our 2-3 weeks quicker than those who were stuck at the lower end of the ladder, essentially rewarding their skill. Of course both had their issues - we didn’t have the Valor or Conquest catchup back in the day (where the cap kept increasing each week), but we do now. Combining those two would create a very player friendly progression system.
On top of this of course, to avoid people sitting at a high CR in PvP for gear, they should be required to have won at least 10-15 games each week in their highest CR bracket.
But instead, right now, we have the Weekly box. The upside to the Weekly Box is that you can actually get another roll at the desired raid items that used to be normally unavailable in the old days. The downside is literally everything else. The RNG is exceptionally unfair - if you loot your BiS PvP weapon the 1st week, not only did you just get tens of thousands of honor for free, you also have the best item in the game for literally no effort. The same goes for PvE boxes.
- Warforging as a means to keep people “engaged”
As of right now, you can potentionally proc: avoidance, leech, speed or a socket (or any duo of these). The intent (from the player’s perspective) is to keep your monthly subscription rolling, because getting BiS is artifically gated behind extreme layers of RNG.
Just get rid of it, and add natural sockets and tertiary stats to gear.
- Crafting forsaken in favor of absurd grinds
There is barely any point in crafting anymore. Since there are no natural sockets anymore, Jewelcrafting is almost completely useless, gear-crafting professions are only useful for crafting 200ilvl items and the occasional base item for a Legendary, inscription is straight up a cosmetic profession at this point, with the remaining professions being Alchemy, Engineering, Enchanting and gatherer professions being semi-relevant. Instead of being able to create great items and selling those (and they don’t neccesarily need to be BiS items!), the players are instead encouraged to engage in grinds that are monotonous and boring with massive gear gaps between players.
Tl;dr - player agency and player-friendly systems are important.