Is the real in-universe reason you can only have 6 pokémon in order to prevent mass Pokémon smuggling?

It might seem suspicious to see a trainer with a huge number of poké balls— what do they need all those pokémon for, anyway? Where are they taking them all? Etc.. It could be a way to prevent wild Pokémon trafficking in large numbers.

Having lots of Pokémon on you at all times might also make you a target for muggers and the like, so I guess it could be illegal as a precaution, too.

This makes me wonder about the consequences of allowing every trainer to capture an infinite number of pokémon to begin with— I’d imagine that might cause problems with poaching, endangered species, ruining ecosystems etc.

I think it’s plausible that only certain trainers with permits (I.e. trainers given pokédexes) are granted the license to catch as many pokémon as they desire, for the purpose of completing the Pokédex / scientific research.

There’s probably nothing more to it than “game mechanics”, but I like coming up with these things for a more realistic Pokémon world! Let me know what you think.