>>34538896>>34538920At the time Ruby and Sapphire released it was completely impossible to catch 'em all, as only a handful of existing Pokemon were availible in the games and there was no backwards compatibility to GSC. If you actually wanted to catch 'em all in Gen 3, you had to wait until the next two game releases and buy those too. People call Gen 7 a cash grab for forcing you to buy USUM for the new Ultra Beasts, but at least it was actually possible to get all the Pokemon that existed in SM without waiting a year to buy the same game again.
On top of this, the fact that Rayquaza, Air Lock, and the Sky Pillar existed also indicate Gamefreak already another story planned out but decided to withhold (though this isn't nearly as big an issue).
Yellow has no content that isn't in Red Green and Blue (unless you're telling me Gamefreak had already planned to add a Jesse and James fight in the game before the anime even existed, assuming that even qualifies as content). Crystal doesn't have anything GS doesn't except the Battle Tower, which you have no reason to believe was planned at the time Gold and Silver came out.
Stop talking out of your asses, underages.