Ngl that moment gave me legit nightmares when I first saw it, even tho Piccolo is my favourite character I sometimes just skip Cell's early interactions with him because I still find them disturbing (honestly feels more like a Seinen than a Shonen imo).
Yeah in terms of horrifying moments I feel like the sheer scope of this often gets understated or ignored: the OG timeline where most of the Z-fighters are dead, where F.Trunks had to go through pretty much every form of trauma conceivable just to create better future for the surviving Earthlings, having to deal with the Androids, Cell, Babibi, Dabura, etc only for his efforts to be rendered pointless in the end thanks to Goku Black and Zamasu killing the last of his family (his mom) and despite his best attempts to once again create a better future using time travel, the OG timeline was simply ment to be the "worst timeline" and got erased by Zeno (keep in mind all the dead Z-fighters, Earthlings, innocents, etc in the afterlife also got erased too aka "super" dead).
Now Future Trunks and Future Mai are the only survivors of the OG timeline living in an alternate world with likely survivors gulit, that's a pretty bittersweet and messed up conclusion.