...The Steven / White situation could literally only have worked with their exact two characters.
Steven can't Talk-no-jutsu everybody. Only people who are undecided.
He couldn't do it to Jasper or Aquamarine, for instance. And they're not even human!
White is immensely powerful in the physical sense, but mentally and emotonally she was inferior to most human children. She could ignore or silence almost anyone who would call her out on her shit.
The ONLY person she was somewhat vulnerable to was Pink because she represented the weakness she (thought she) had banished from herself - emotion. Pink had a clearly defined function: entertain her sisters and thus help them relax. No lesser gem would be allowed to be so intimate.
But she proved imperfect, calling into question the perfection of the whole system, causing White to withdraw into herself so she could pretend at least she, herself, was perfect even if everyone else was not.
The shock of realizing Pink still existed, dared to confront her and proved beyond her power (because of course he was... pure emotion always trumps reason) was more than her rigid mind could handle. Diamond is very hard, and it does not bend, but it can break, as it were.
Only Steven could have done that to only White. Yellow never believed she was perfect, she just worked very hard and strove to be as good as she could be. Steven could never have caused such a shocking realization in her. And Blue was paradoxically invulnerable to this for the same reason Lapis could defy her own power.
Only someone who believes they are absolutely perfect can have their worldview shattered by having one single tiny imperfection pointed out to them.
If the pacing on this had been better it would have been almost perfect.