you literally could, it was called the National Dex 
honestly, as i’m hearing it, Gen 9 has the best competitive balance but i still don’t think it’s a major factor in what makes the game good as a whole when the mechanic itself is, at least to me, not that interesting. that said, i am admittedly biased and enjoy things open for design like Mega Evolutions (i think Gigantamax is a cool concept but don’t enjoy the designs they’ve made for it)
Sun Moon hits the beats that Scar/Vi want to aside from the legendary companionship, which i actually quite enjoy. don’t ignorantly lump me in with Gen 5 lovers when all i said was that it seemed good bro 
cool, they shouldn’t be happening at all when you consider how much Gamefreak is ripping you off for it.
i love pokémon as much as anyone, hell it is one of the main inspirations for my art and career, but you are settling for the least and it’s kinda sad to see Gamefreak apologists paying nearly three times as much money for a literal fraction of the content Gamefreak used to include