>>58953555I think the solution is to prevent fully-evolved Pokemon from being caught.
It makes sense to see rare and powerful Pokemon out in the file. But I also agree that being able to just catch them cheapens the experience, figuratively and literally, with catching, training, and evolving the pre-evolved forms.
So instead, make them into overworld mini-bosses. They cannot be caught, but in exchange, knocking them out yields a ton of experience and other helpful in-game items.
That way there is still a chase and reward for finding and battling them. Plus, if you see one, you know that its pre-evolved forms are nearby. So you can still get a Dratini to eventually have a Dragonite of your own.