I agree with you in terms of Pokémon - it's an awesome world to live side by side with Pokémon in any case :)

In terms of DBZ however, You stated earlier you could just wish yourself to be the strongest being in the universe - that sounds pretty evil to me, and to hide that fact from Bulma (through lying), would still be evil. So in that sense, being a sneaky liar is the only way you can get by in the DBZ world, unless you want to do with being a petty human without any potential or future outside of simple work in the human cities.

If you are a weakling to begin with, which is highly thinkable, then how do you intend to gather the Dragon Balls without contest? Do you expect to be the only one knowing of their existance? You'd, in theory, thinking of how many times the main characters in DB gather the Dragon Balls, be facing the main characters of the show, along with any kind of bandit organisation which is also out to get them. Good luck with that.
Even more thoughtful is: How do you imagine that you, of all people, would gain the information about the Dragon Balls' existance? So many people on planet Earth have no idea that such a thing as Shenlong exists, and you are most likely never to know either.

In pokémon, the main protagonist is seemingly pretty much the only one who manages to improve and travel around - what are the odds that you can reach the kind of level of ability that the main protagonist will always reach? You will have a place in society - a family, friends, whom you might not wish to leave - think of all the people in cities who simply live their lives there, living with their pokémon along their side in a peaceful society. You could easily "spawn" as one of those people.

if we are just spawning in as a current character then you are right both realities would be useless. But if we go in as a fresh starter with our current knowledge of the universes then in DBZ simply use the technology vastly available and possibly befriend bulma and use her dragon radar because since you arn't using it for evil they should have no problem. As for pokemon starting fresh you would have unlimited potential as it would be your choice to train or not. If you choose not to train then you still get to hang around with pokemon which is still pretty cool.

So it really depends on how you would enter the reality as to your potential.

I agree with you in terms of Pokémon - it's an awesome world to live side by side with Pokémon in any case :)

In terms of DBZ however, You stated earlier you could just wish yourself to be the strongest being in the universe - that sounds pretty evil to me, and to hide that fact from Bulma (through lying), would still be evil. So in that sense, being a sneaky liar is the only way you can get by in the DBZ world, unless you want to do with being a petty human without any potential or future outside of simple work in the human cities.