Dude, I did a run with Chikorita as my starter at some point and that thing is actually good. Synthesis is some heat. Who needs Super Potions when you can just spam this early game healing move? And doesn't it learn Nature Power? I remember it being viable in the ice gym for some reason.
Now if you really want some trouble, pick Bulbasaur. That was a pretty unfortunate pick for me. Let's see, what good moves does this get? Take down/Double Edge (recoil), Solar Beam (needs Ninetales to come in first most of the time), Petal Dance (can't switch moves), Petal Blizzard (it's alright as long as its single battle, which so happens to not be the format for a lot of the boss battles). Fuck, this brings back terrible memories. Like great, you get Synthesis basically at the point where you can easily buy good healing items and probably have a solid moveset. The only good thing about this starter is that nothing outspeeds once you get your sun up. Well, I guess you could use Petal Blizzard in doubles with a Sap Sipper mon next to you. If only I knew about that ability back then whoops.