Why is frustration no longer considered against damage in a champ's power budget?

The amount of utility packed onto new champion kits is absurd, and it's part of the reason the mobility burst era is happening. Making abilities simpler, or sticking to one effect per ability, would help this game slow itself down. Too many champions have too many options and effects that they can fall back on. % max hp damage is rampant, true damage used to be considered heavily and was inherent in a champ's kit There is a reason there has never been an item that granted a real true damage effect, and that reason is why everyone hates Conqueror. There is a reason Xin was nerfed and reworked several times, and those same reasons are why we all hate Camille.

If we don't learn from the mistakes of past items and kits we will continue to repeat them. Over, and over, and over champions are released with these insane kits, and the biggest singular effect of that is even if they're not overpowered, no one wants to play against them

That's a huge issue, and there are very few old champion kits that I used to despise like I do some of the newer ones. Playing against a champion that can utterly dominate the flow of the lane/teamfight is never going to be fun. Frustration needs to be taken into account. That can't be overstated.