So I wanted to give my Diablo 4 beta feedback and decided to focus on my biggest gripe, and something that has been already present in previous Diablo games to varying extent.
I think I speak for many if I say that building your own character with the expression of a certain amount of individuality is very important for players. There must be also a freedom to choose between different playstyles. Or, as some people call it, create your own “build”. Of course, apart from pure gameplay things like character appearance and cosmetics play a role for some players to varying degree, but I will purely focus on gameplay here.
Attributes, skill points
In Diablo 1, you gained attribute points through leveling. In addition you could learn certain spells (which were most useful for mages, somewhat useful for rogues and least useful for warriors) by finding skill books. The randomness in finding skill books was not allowing as much freedom to build your character, however it certainly led to more individual characters (since not everyone found the same) and you still had a certain amount of choice after finding several books what you really want to use.
In Diablo 2 a skill tree was introduced instead, and with each level and a few quest rewards you gained points to distribute on your own, and every class had their unique tree - great! A downside is that people tended to not spend their points but rather save them up to invest them into later tier skills, because early game skills do not scale well into the end game, and the early game was easy enough without heavy point investment.
In a later patch a new “synergy” system was introduced, and unlike many other players I think this was a step backwards. While (in some builds) it gave you a reason to invest more points into early game skills, it also significantly reduced your freedom on how to invest your skills. Like before you had around 100 points to distribute up to max level, but now instead of 20 skill points sometimes 60 or even more points were needed to maximize just your one attack spell. That means you have less points available to invest in other utility skills or maybe a second or even third attack spell. You now were compelled to put nearly all your eggs in one basket.
Diablo 3 got rid of the attribute points then as well as skill points. Now every sorcerer at max level was practically identical to anyone elses sorcerer, there was no individuality. On the other hand you had more freedom in choosing your playstyle as you had all skills unlocked and could freely choose (at least on paper; see in the “Items” chapter why in practice this was not the case). However you now also could only put 6 abilities in your skill bar, which limited the freedom again. The rune system was a neat introduction, adding 5 specialisations to every skill to choose from as well.
Diablo 4 still has no attribute points. However the skill tree is back. I cannot comment much on the quality of the skill tree yet as we couldn’t play a late game build, however while it is positive that you don’t need to put as many points into maximizing one skill, you also still can only select up to 6 skills in your skill bar, so I am not sure how much of a difference that will really make. At least it seems feasible to have two different attack skills at the same time (alas, see “Items” chapter).
As a side note, the skill specialisations in the skill tree are functionally similar to D3 runes, only there are now just two instead of 5 per skill - big step backwards.
Items
Items in Diablo 1 and 2 certainly came in different qualities and contributed to the power level of your character in a meaningful way. They didn’t fully determine your build though, but just supported it. Your class, attributes and skill points largely determined your play style.
In Diablo 3 you introduced legendary and set item effects that massively boost individual skills and thus playstyles in such an absurd fashion that they fully dictate your playstyle. If you have an item that boosts the damage and effect of one individual skill in such a way that it becomes effectively 10x as strong as baseline, you are always going to play that skill. And if you then find an item that boosts another skill by that much instead, you are only going to play that skill. And if you can stack multiple effects on the same skill or skill category, you will not branch out to multiple ones as well. Thus your build fully depends on the items you have available and equipped. You can choose between playstyles if you already own a lot of top tier items to choose from, but otherwise your freedom is an illusion, unless you are content being much less powerful. Your items do not support your individual build, they dictate your build.
In Diablo 4 I haven’t seen late game items yet, but at level 20 I already found a druid item that boosts the damage of my companion skills by +200% and also summons one additional companion, so my poison creeper skill for example is now effectively doing 600% damage - just by finding an item. That makes me fear that we will have the same issues as in Diablo 3 again. Your items will again dictate your build and since you can freely respec your character, you are going to.
The only positive side is that you can transfer legendary item powers to other items, so at least once you found and unlocked some, it should be easier to have late game items with different choices of powers. But if it takes too long to unlock them all, it will feel bad
Summary
In my opinion the character power in Diablo 3 is too dependent on your items rather than your individual build decisions, and I fear that Diablo 4 will be too close to Diablo 3 rather than Diablo 1+2 in that regard. I think too much character power coming from items leads to a lack of freedom in your individual build and playstyle choices, because the bonuses are so large that they dictate the rest of your build.