If Sun and Moon is in the discussion, I'm gonna say straight up, the game's story is objectively worse for the player character's involvement and presence. Other iterations like the Manga fare better, but the incarnation of the story found in the lauded SM games is not the good one just because it shares those writing elements. I'd go as far as to say SV handles the thematically similar plot beats and structure better.
Game Freak didn't feel confident giving the PC a personality while simultaneously being too afraid to give major plot moments to anyone besides you: despite being an outsider to the Aether Family, you have to rescue Lillie and Nebby, then accompany them through the Ultra Space confrontation up to Lillie telling off Lusamine for being a horrible parent. That moment kind of gets undercut for me by the fact that when Lusamine becomes the Mother Beast, she battles you until Nebby decides the plot's over and roars the Jellyfish off her. To a lesser extent this persists even into the USUM rewrite where Lusamine screws everything up and Nebby is taken protecting Lillie, only for you to go and fight Necrozma yourself. In both games this culminates for me in you essentially being given the fully evolved Nebby, completely superfluous since the game includes an event to obtain your own Cosmog that can evolve into the same form anyway.
For all the criticism levied against the BW plot, as least there is a purpose to your character's existence in the narrative (challenging Team Plasma and becoming N's opposite with the Tao Dragons is what pushes him to reflect and deprogram his upbringing). BW's plot structure does not function as or more effectively if the player's role is removed without being filled in.
SV splits the player's attention between the three plots on smaller scale conflicts while connecting with the friend group before introducing the higher stakes plot in the endgame. Your character is designated as one of several people with a role to play in the Area Zero excursion: Arven knows the area, Penny is intended to understand the tech (I'll admit flat out this isn't utilized significantly), Nemona is additional muscle to reach the depths, and you're the trainer the "Professor" entrusted with the injured Raidon (given the territorial one is also extremely dangerous) to bring the team down. While Arven has a history with Area Zero, the stakes are bigger than him and the present situation isn't presented as "his" to handle anymore than it is yours, compared to SM's Lillie/Gladion/Lusamine conflict being personal within the family that your PCis just kind of an observer for that Lusamine decides to fight near the end in Ultra Space.
The central element to all this for me though is the trauma victim and how the game handles their narrative role. Lillie is presented as a child around the player's age, but despite the series history and the arc they want to give her, she remains a very passive character until the Aether incident, at which point she speaks her mind but hasn't been developed enough to display agency or capability to take action since that would have taken away from the totally-not-gym-challenge structure the player's doing while just leaving her at various safe locations. By comparison, SV makes the traumatized party the player's Raidon, who is presented as on the more animal-natured side of Pokemon behavior. Despite this, the player can witness a more gradual growth in the mon as it regains its forms from the territorial injury and they travel the region as a pair, setting up the payoff in the ending where not only is your partner fighting fit again, but they don't hesitate to fight their previous attacker (as opposed to trying to take you 4 and escape as the AI suggests).
Game Freak didn't feel confident giving the PC a personality while simultaneously being too afraid to give major plot moments to anyone besides you: despite being an outsider to the Aether Family, you have to rescue Lillie and Nebby, then accompany them through the Ultra Space confrontation up to Lillie telling off Lusamine for being a horrible parent. That moment kind of gets undercut for me by the fact that when Lusamine becomes the Mother Beast, she battles you until Nebby decides the plot's over and roars the Jellyfish off her. To a lesser extent this persists even into the USUM rewrite where Lusamine screws everything up and Nebby is taken protecting Lillie, only for you to go and fight Necrozma yourself. In both games this culminates for me in you essentially being given the fully evolved Nebby, completely superfluous since the game includes an event to obtain your own Cosmog that can evolve into the same form anyway.
For all the criticism levied against the BW plot, as least there is a purpose to your character's existence in the narrative (challenging Team Plasma and becoming N's opposite with the Tao Dragons is what pushes him to reflect and deprogram his upbringing). BW's plot structure does not function as or more effectively if the player's role is removed without being filled in.
SV splits the player's attention between the three plots on smaller scale conflicts while connecting with the friend group before introducing the higher stakes plot in the endgame. Your character is designated as one of several people with a role to play in the Area Zero excursion: Arven knows the area, Penny is intended to understand the tech (I'll admit flat out this isn't utilized significantly), Nemona is additional muscle to reach the depths, and you're the trainer the "Professor" entrusted with the injured Raidon (given the territorial one is also extremely dangerous) to bring the team down. While Arven has a history with Area Zero, the stakes are bigger than him and the present situation isn't presented as "his" to handle anymore than it is yours, compared to SM's Lillie/Gladion/Lusamine conflict being personal within the family that your PCis just kind of an observer for that Lusamine decides to fight near the end in Ultra Space.
The central element to all this for me though is the trauma victim and how the game handles their narrative role. Lillie is presented as a child around the player's age, but despite the series history and the arc they want to give her, she remains a very passive character until the Aether incident, at which point she speaks her mind but hasn't been developed enough to display agency or capability to take action since that would have taken away from the totally-not-gym-challenge structure the player's doing while just leaving her at various safe locations. By comparison, SV makes the traumatized party the player's Raidon, who is presented as on the more animal-natured side of Pokemon behavior. Despite this, the player can witness a more gradual growth in the mon as it regains its forms from the territorial injury and they travel the region as a pair, setting up the payoff in the ending where not only is your partner fighting fit again, but they don't hesitate to fight their previous attacker (as opposed to trying to take you 4 and escape as the AI suggests).