My personal opinion is that tanks mainly need a power shift, not nerfs specifically, but so do some fighters. The issue with tanks is that, over time, they've experienced significant increases to their damage, mainly with buffs to their bases and much more target-agnostic damage, but have also lost a fair amount of durability in the late game. This has ended up making them more similar to fighters, whose niche has always been that of the tanky damage-dealing class, creating an even greater overlap between the two classes. Tanks currently have the advantage right now because, unlike fighters, they can go for full defensive builds and still deal decent damage, whereas fighters that try the same (and are pushed to do so due to the high amount of damage in the game) end up taking and dealing less damage. In turn, this has caused several divers to go for Lethality instead and turn into assassins, namely Wukong and Jarvan IV.
Because of this, I think tanks really need to lose damage, even if this hurts their waveclear. If tanks really need to clear waves, which I don't think is nearly as much the case as several players claim (tanks aren't intended to contribute damage), then they could receive amplified damage on their bread-and-butter damage source against non-champions, but otherwise they shouldn't be able to deal significant damage to champions unless they are specifically designed to do so. Moreover, target-agnostic damage is not something tanks should be given in abundance, because they aren't meant to out-duel fighters. In fact, target-agnostic damage is a more appropriate strengths on fighters, not tanks, and as such I think we need to stop balancing tanks as if they were fighters.
Another problem the OP mentions is that of CDR creep, and that I agree has caused many tanks to become significantly more frustrating, as the uptime on all of their CC has drastically increased. This has affected fighters especially, since the class is most vulnerable to crowd control, but also because a lot of tank CC is not put into displacement, which ignores Tenacity completely. Because of this, I would also want to tone down crowd control in view of what has essentially translated to a 33 to 67% increase in CC uptime. However, I think this should be implemented on all classes, not just tanks, and I think fighters in particular need to lose a lot more CC in their kit, because otherwise we'll just go back to the days of Seasons 2-3 where most fighters were just better tanks. Both tanks and fighters should be durable, but tanks should specialize in CC while fighters should specialize in damage: as such, either class should only have access to the other's strength if they are deliberately meant to have some overlap, and not because they "need" the effect to work (they usually don't).
One problem I'd like to see addressed, if tanks get changed, is that of tanky itemization: the ongoing problem has been that tanky items provide too much raw durability, to the point where many damage champions have been able to purchase the stat and succeed with it, with many unhealthy side-effects. Additionally, one other problem I think is related to this is that tanks have a) become less durable due to tanky item nerfs, and b) still lack skill expression compared to many other champions, in part because they still end up turning into walking sandbags of health and resists. Fighters also suffer from this problem, to some extent. Because of this, I think Riot will inevitably have to change this by placing the power of tankiness onto kit scalings, rather than solely onto items. Making tanks more vulnerable if they don't use their defensive effects properly, but rewarding them with much more durability if they play correctly, would add much more skill expression to the class, and so in a manner that would also make players memorize the champion's own play patterns, and not just rely on general game knowledge. Additionally, if tanky items were nerfed, but tanks and fighters had health/resist scalings added or increased on their kits, tanky itemization would not longer be attractive to other classes (who therefore wouldn't be forced to snowball as hard off of damage items), but would still work on whichever champions it's intended for.
The TL;DR to this, imo, is that I believe that tanks should receive nerfs to their damage, because they're generally not meant to output it in significant amounts, and to their CC, because it's crept up to unhealthy amounts with the increasing commonness of CDR. However, I think individual tanks and fighters need to have their innate durability increased in relation to their defensive purchases, so that they can express their own tankiness in a more skillful manner, and therefore get to become more durable under the right circumstances. Additionally, I think there needs to be a general power seep, which should affect the damage, CC and even utility of many more classes than just tanks.
and the base damage on his e, and arcane comet was too much for me.
