The problem is those lens fucking suck. It makes them boring.
Sun and Moon says, "We will not be a generic Pokemon game, we will have Lillie command her Pokemon (a legendary) to attack her Mother's beast form after 20 hours of build-up to this conflict." Ultra Sun and Ultra Moon says, "You will go on a solo journey with the cool legendary bringing you to fight Ultra Necrozma alone."
But part of the whole problem with third versions is that you’re playing the same game twice. Ideally, I don’t actually want USUM to repeat much of
anything from SM, because I already played those games. I don’t want the same story that I already enjoyed just repeated to me — if I wanted that, I’d just play SM again.
At the very least, diverting the climax into a different story helps to make it feel like a little less of a retread. Like at least they’re using the material to do and say something a little different with the characters. Lillie definitely gets the short shrift in this exchange, but the greater focus on what makes Hau, Gladion, Guzma, and Lusamine tick takes advantage of what USUM is doing differently with the scenario. (And even with Lillie, I can sort of see what they were going for — by keeping her around at the end, we get to see the start of her journey as a Trainer.) Necrozma also ends up more characterized than any of the previous third version mascots, because the story is constructed around its predicament and how that has affected others.
It's also funny that Lusamine is essentially proven right in her horrible shit that she still canonically did (literally abusing her kids, seemingly killing Pokemon) and now that she isn't the major antagonist, she's just. There.
Not really?
Lusamine isn’t “proven right” at all; it’s explicitly her arrogance and messiah complex that causes her to rush into Ultra Space to go deal with Necrozma, thinking she can handle it all on her own and disregarding the plan that the Ultra Recon Squad had devised with her. And what happens? She gets her shit rocked, and Necrozma catches everyone off-guard and fuses with Nebby, which just hurts all parties involved. Necrozma is pained by the light it can’t control, Nebby is suppressed, UBs are dropped all over the region, and Alola is left on the brink of doom.
That’d be a weird way to say “See, neglecting her kids was justified!”
And then her post-game interactions are a parade of “Here’s where I went wrong; I’m acknowledging that and trying to do better” admittances.
>
"Caring won't keep the things you love safe. But if you don't care, if you're so hard at heart, you may find you have nothing left to protect... Is that it? Maybe I can understand Lillie a little better now."
Here she’s recognizing how being overbearing accomplishes nothing, while failing to attend to the needs of those you claim to care about only pushes them away.
>
”I'm in no position to face my children now... I've lost any right to claim that I am protecting Pokémon as well... If I can't be a mother to them, and I'm no longer worthy to be the president of this foundation... then what am I to be?”
>
“I am Lusamine. I am the president of this foundation and mother to Gladion and Lillie. And while I will pour my love into protecting Pokémon and my children from pain... I will also try to be strong enough to watch over them without interfering from now on. That would be an even more beautiful kind of love, wouldn't you say? I learned to think this way after watching you... young <player>."
Here she’s actively holding herself at judgment for what she did, and reconciling her overly protective behavior by deciding that she has to learn to let people grow on their own while offering unconditional support.
>
"After all, the way he smiles now... It's quite lovely, don't you think?"
And now, having taken those steps, she’s even able to let Mohn go and finally move on from the grief that caused her to become so malignant.
