because dukkha is completely eradicated in both Buddha and arhants.
saṅkhāradukkhatā only exists for the arhant in the terms of SN 12.27:
“Then is it that Master Gotama does not know and see suffering?”
“It is not that I do not know and see suffering, Kassapa. I know suffering, I see suffering.”
they know and see suffering but without experience of suffering. Such thing is not possible after the cease of ignorance, consciousnes… clinging, becoming and so on.
There is no Reality arising conditioned by ignorance and giving rise to dukkha. Please also read my previous answer to @Ceiswr
I suspect the core of the the apparent disagreement is in what I wrote to @Ceiswr:
Dukkha is not a dhamma. There is no possibility of dukkha without the clinging to an existing -self to sustain dukkha. We can name that TV image “dukkha” but this is just the sustaining of a concept, this is not the description of a reality with dukkha.
If you or @Ceiswr check any contradiction please explain this with detail. I would be glad to know. . 