One of the biggest problems with itemization in Diablo 4 is that many/most unique items are generally lacking utilization in any optimized endgame builds.
This is because most of the uniques aren’t better than the legendary aspects that most endgame builds revolve around. The developers that don’t play the game aren’t going to understand because the game generally looks good on paper.
I looked through Diablo 4 skills for all of the classes when the game first launched and I felt it looked good (on paper) overall, but it didn’t take long to realize that functionally, there is a lot of dead weight.
Classes aren’t really designed with a solid basic/core synergy framework and too much of every endgame build worth a damn relies heavily on aspects just to function. It takes too much effort to optimize itemization and skills and paragon min/max clusterf***ery to even know what the best combination is for the direction you’re going with a class.
There’s a real headache just altering your build because you have so many elements that have to change beyond just the skills. When your build is updated (either by yourself or someone else), you now hunt for new items because tempering bricks on bad RNG. New optimization may require a different stat priority that your current gear won’t allow.
So I feel the best way to fix this is to add a way to equip aspects separately from worn equipment (kind of like the vampire powers tab in season 2) so if you had a unique, you could still keep the aspect your build needs (via the aspect tab) and you’d also get the unique bonus you can’t get without equipping it.
I envision that the aspect tab would have the same slots (and rules) your worn equipment would have, but you would have to choose between the aspects on the worn gear or the ones imprinted on the aspect tab for each slot (this would also allow potential for dual builds for trash and bosses you could swap on the fly).
This would prevent you from getting more aspects than currently allowed, but unique bonuses would no longer conflict with aspects so uniques would always be better than legendaries for each slot as long as they provided a bonus that was applicable to your build.
This would make uniques much easier to use and balance without removing the vital aspects each build relies on. It’s just so disappointing that uniques are so often useless even though they should be better than legendaries. The only way to truly fix this issue is to remove the competition between unique bonuses and legendary aspects.
The other solution (not recommended) is to actually make the unique bonuses better than the aspects they replace, but that is a much, much more complicated fix and it would also negate the point of even having aspects if they succeeded in making uniques better.
Ultimately, I feel having both uniques and aspects for every slot is best because it doesn’t negate the benefit of aspects, but allows you to actually enjoy the fun of unique bonuses. Having to choose either or is never going to be good enough. So many endgame builds use zero uniques. Even those you think should be better… apparently are not, according to the numerous guides.