Yeah, I don't know what's going on with the Revisionist History. SSJ2 is perfectly fine. As are SSJ Grade 2 and Grade 3, as they served as foreshadowing/precursors to the SSJ2 form Gohan takes, especially in providing the means of which Gohan's character arc is completed. It should also be noted this theme that Gohan undergoes is maintained in the Buu Saga for other SSJ2 users. Vegeta doesn't go SSJ2 (even though we know he has it) until after he self-destructs and completes his arc, and Goku doesn't go SSJ2 until he fights Vegeta and challenges him on his fall into Darkness (unless you want to count the Yakon "blip" as him actually transforming all the way for a fight), and to convince him to snap out of it.
SSJ3 is useless, yeah, but that was the narrative point. It's supposed to break the trend of "new threat, new form.," that had started to become a factor after Saiyan Saga (Kaioken {Saiyan Saga}, Super Saiyan {Frieza Saga}, Super Saiyan 2 {Cell Saga}), and establish that this Saga won't go the same as it previously did.
SSJ4, and Super Full Power Super Saiyan 4 (for reasons I'll soon go over) are peak.
SSG is also good, Narratively speaking, Goku is ascending not towards the Gods not because of his “unga bunga strength” or “big mad,” but because of his GOOD DEEDS. This theme is very prominent in Dragon Ball and is acknowledged twice—Once at the 23rd Tenkaichi Budokai and yet again at the Tournament of Power. The opportunity to turn into a Super Saiyan God came not from strength, but from Goku’s ability to see kindness in others and grant them the ability to improve themselves as people, which they then do good on. It’s those people who then give him the power of a God.
SSB is ass.
SSJ Rage is ass.
SSBE is...eh. You could make the argument that Vegeta gets Super Saiyan Blue Evolution from his tapping into the good will (promises/dreams) of Saiyans from another Universe. His Student, who he lost. It’s made explicitly clear that, narratively, this form is the reward for not only having changed, but seeking to grant that change to other Saiyans. You can even add in his insecurity over the Saiyan race into this, as Zamasu steals the embodiment of the changes Saiyan (Goku) and perverts it—Hell, he becomes a better “Saiyan” than Goku or Vegeta were with it, and you can reason this shook his beliefs. Which in itself can be supported with the Bulma scene—Vegeta realizing that not even his wife views him as a solution to the problems, and instead relies on Goku. But at the same time I'm not very enamored with it, and it feels like it was just shoved in to give Vegeta a SSBKK equivalent.
SSBKK is Super Saiyan Blue Kaioken by tapping into the power given to him by a friend—Which he specifically met from his own good will, as that is what got him the opportunity to train in Otherworld with his physical body. It's basically the furthering of the themes of SSG. Very meh outside of hype factor.
UIO-MUI is peak.