The means were also quite humane. Transporters aren't generally portrayed as being painful and they're quick. Janeway's disposal of that abomination was an act of mercy.

Born with female sexual characteristics. Assigned female at birth by their parents without consent, which is a horrible imposition of someone else's will upon them. Taken by the Borg, stripped of markers of human femininity at a biological level, assigned the identity of drone in place of gender without consent, which is a horrible imposition of someone else's will upon them. Ended up on Voyager when it escaped the Borg, cut off from the collective, body began rejecting implants, cried and said they didn't want to be human, and Janeway ordered surgical removal of implants instead of looking for a way to preserve them. Told to "become a woman", introduced to human culture and sexuality in aid of this goal, assigned female without consent, which is a horrible imposition of someone else's will upon them.

7/9 was forcibly assigned a gender with no say in the matter a total of 3 times. Our western culture is biased towards treating binary gender as normal and essentially good, so the actions of Janeway and the Hansons are normalised and excused, the violence inherent in them erased. But the fact of the matter is, nobody ever gave 7/9 a choice in the matter of their identity. We don't know what 7/9 would have chosen if they had been allowed to develop a sense of themself naturally, because three different groups all independently took that choice away. The Hansons, the Borg, and Janeway are all moral equals as far as 7/9 is concerned.

And I say this as a nonbinary person, who is dronegender, and who empathised with the horror and misery of 7/9's detransition story. The science fiction story of the violence inflicted upon 7/9 is a perfect mirror of the way my own life feels, and it felt good to see that pain recognised on TV for the only time that someone like me has ever been represented.