>>56150992It all depends on the game. In Kanto, you can't get anything good beside your starter before Celadon City, and you don't want a team of six anyway because you'd be spreading your exp too thin.
In the Johto games you don't get anything until you beat the game.
Ruby and Sapphire are when GF realized that if all the good pokemon are packed in the end, players are just going to sweep every battle with their starters, so you get a steady supply of cool new additions from route 102 to Victory Road. This is how most pokemon games are designed.
SV finally gave the player full agency about catching pokemon, and hopefully the next game will as well.