>>48895618Sure, you can have non-evo mons. Kanto had a lot of them, too. However, those were incredibly strong mons who were viable despite not evolving. Smeargle, Dunsparce, and Murkrow were garbage to use.
Johto's dex problem is much more apparent when you take into consideration a few things:
1. Red = can't evolve
2. Blue = Baby forms not found in wild, only acquired through breeding
3. Green = Can only get via trading.
That means if you're playing Pokemon by yourself (You had to be very lucky to be a kid with two Gameboys and both versions, or otherwise find "that one kid in class" who had a link cable) when GS came out back in the day, that means your first run through Johto was going to have a very stagnate selection of mons to use in your party. You couldn't run into the blue ones, most of the red ones would get severely outclassed as you kept playing, and you couldn't acquire the green ones.
And on top of that, you have the additional problem where the original mons you can get that have evo lines have awful stats. Noctowl, Furret, Ledian, Ariados, and Togetic are super fucking weak. Why is Furret so terrible compared to Ratticate? Even Beedrill is pretty decent in Gen 1 if you decide to stick with him. Pigdeot is amazing.
There's a reason why a lot of teams in people's GS runs end up including a Crobat, Quagsire, and one of the Eeveemons.