This. I mean my issue with Rose as a villain is that he doesn't work as a "summon the legendary Pokemon" villain, which is the role he's place in games. Rose as an antagonist who (intentionally or not) made the lives of his employees (the gym leaders and champion) hard because he's thinking in business terms would've been interesting to see (and to be fair that is part of his portrayal in games), it's just adding the Eternatus plot to his character just derails it. Not to mention (as I've seen from others) that in this day and age where climate and energy issues are a thing, making the antagonist someone who supports an alternative energy source (even though granted it was dangerous and an ill-thought out plan) is not the best look.
Contrast that to the royal twins, who have in my opinion a more understandable reason to "summon the legendary Pokemon". Sonia's spending her time uncovering the truth of the Darkest Day, a truth that would put their royal claims in jeopardy. So them acting out to the point that they decide to recreate the Darkest Day to prove their claims would've made that narrative make far more sense. Plus the storytelling potential around a historical coverup and nobility would've been really interesting to see.
Something I had some thought about shortly after going through the Sordward and Shielbert story is that they could've had a villainous team of their own too, made up of various people in Galar they've convinced are the real descendants of royalty, and it would've given them more credibility instead of being these two random strange looking people. On the other hand, perhaps it's to the best they didn't, since it could cut a little close to some political issues in various countries.
I don’t think Rose is actually a villain. He wasn’t really doing anything that evil or even for selfish reasons. He just didn’t understand what the Darkest Day really was (Which is no one’s fault as even Sonia had no idea about it being about Eternatus and she was researching the event the entire game) or that it would end up being so destructive. Rose sort of is like Lusamine. Both aren’t actually evil and did truly want to help both Pokémon and humans and their organizations weren’t evil either. The Aether employees only attacked you because you technically were trespassing and they were concerned for the safety of the Pokémon being housed in the building and they had no idea you only were there to save Lillie. Lusamine went off the deep end only because Mohn went missing and she desperately wanted to find out where he was and bring him home in SM. In USUM, Lusamine wanted to make sure that Necrozma didn’t pose a threat to Alola and she did seem to understand that if it wasn’t weakened and forced to be put under control, hundreds of Pokémon and people would be harmed from a rampaging Necrozma. I mean physically forcing Nebby to open a dimensional portal is cruel but she had to do whatever it took to get into Ultra Space.
I feel like Chairman Rose was a character Game Freak had a lot more planned for but had to scrap a lot of it. Macro Cosmos is more of a villainous team than Team Yell, since it actually has at least one admin (Oleana) and exerts a greater amount of control over Galar. In addition, Rose Tower had the feel of a stillborn dungeon, with something akin to Silph Tower or Aether Paradise planned out, but they had to repurpose it into one big elevator ride. And he would've been threatening if you opposed him due to the fact that he not only organized the Pokémon League, but Macro Cosmos runs a large amount of businesses around Galar, and thus his presence and his influence is everywhere. As a result, they could've had you go up against Macro Cosmos througout the game without having realized who you were opposing. Since the company mainly does industry, perhaps that factory on Route 3 would've been a violent introduction to their power--which, incidentally, could've been a dungeon, as a lot of dungeons in Pokémon games are industrial in nature (Power Plant, Kanto Game Corner, Goldenrod Tower, Team Rocket HQ, New Mauville, Team Galactic HQ, Fuego Ironworks, Cold Storage, Virbank Complex, Poké Ball Factory, and, again, Aether Paradise). Galar is the only main series region without at least one dungeon with an industrial setting.
The corporate villain is a character type the Pokémon games hadn't done before (even if said character turns out to be an anti-villain), which is why I feel it's such a shame that it always seemed like there was a lot more they could've done. Perhaps many years in the future, when they remake Sword and Shield
and they can make Rose into the character they intended from the start.