This is a belated response, but I was typing something else when I saw your post and it's been haunting me for a couple of days now. Because what are you talking about? #ShinyPokemon is trending on Twitter every time a new game releases, and most of the rest of these things are covered by in-game Trainer Schools. That includes SV's own academy—I'm in Math 6 hearing about STAB from Tyme as I write this, and I recall other games raising the subject much earlier. Folks use these things even if they haven't been online long enough to know the technical term for them.
You'd have to be virtually illiterate to play the games in AD 2022 and never read the PokéDex, never go raiding, never chuck a Nest Ball, never adjust the game options, never discover STAB, or never learn about Shiny Pokémon. They're not as strictly hammered into the player's skull as the ubiquitous catching tutorial, but they're all in the games and often just lying in plain sight for the casual player to engage with them.
Like, EVs and IVs remain pointlessly obtuse, but it's the only thing on this list other than ribbons that's vaguely obscure. Everyone knows about things like opening the options menu and breeding Pokémon, and it's especially younger people with time on their hands (the target audience) that pick up the latter kind of thing. I'm getting older myself, but your estimation of the younger playerbase's level of engagement is ridiculously bleak.
You're not wrong. I want to be clear: I'm not saying your point is wrong. Dare I even say you are right. I'm just flummoxed by the proposition that only 10% of the playerbase would care about the loss of those things. You're not alone in caring about them. Yours might not even be the minority opinion. In the digital age, young people absorb these mechanics faster than ever before.
Still sorry the facilities keep getting knee caped for you though. 
