>>55651426The only game this would actually take some effort in is Gen 2, and that's if you refuse to backtrack or seek out uncommon Pokemon like Miltank and Heracross.
Gen 3 lets you make a full team of new Pokemon before the first gym.
BW2 gives you a healthy selection of both new Pokemon and good old Pokemon like Elekid.
I think that's the other issue with Gen 4, it's not that old Pokemon = bad, it's that for some reason they used the actual bottom of the barrel filler Pokemon people would pass up in any generation. Abra, Machop and Geodude are all not only stupid common, but all 3 are trade evolutions which makes them undesirable for a solo playthrough unless you really don't mind having a Machoke forever. Psyduck is a trash encounter in every game, and Zubat is overlooked in favor of Starly. Meanwhile BW2's early route old Pokemon are stuff like Riolu, Growlithe and Azurill, Pokemon people can feasibly want to run, AND they're next to Gen 5 Pokemon if you want something different.
Imagine if instead of every cave looking like pic related you could choose between stuff like Sableye, Aron and Tyrouge. Do you get what I'm trying to say here? People would be far less likely to run the same teams if they had more than a few good options starting out.