This. So much this.elder wand and pokeball with Arceus
It would be awesome to have a Pokemon, but you wouldn't really be able to show it in public, else you'd end up being some government lab rat or something.
Also, how would you train a Pokemon from level 1? I don't think that the pound is going to let you make all of its animals faint for the sake of leveling (sorry if in bad humor).
Those don't exist in (real) life. I would kill you if you hurt innocent animals.
lol. Your Pokemon would have to be a sekret, so not much fun there.