Only 10% of the population can be in the top 10% of wealth at any time.
What's more important for the majority is how good life is at the bottom half than the top. You're far more likely to get knocked into the bottom 10%, and especially the bottom 50%, than get into the top 10%.
> You're far more likely to get knocked into the bottom 10%, and especially the bottom 50%, than get into the top 10%.
The odds don't say that at all necessarily. That entirely depends on you, your competency, your circumstances, the random events in your life.
Depending on who and what you are, your odds can be dramatically better that you will end up in the top 10% than that you will end up in the bottom 50%.
All people are not created equal and are obviously not born into equal circumstances. It invalidates the premise of applying detached likelihoods (detached from the person they're supposed to apply to) to such a concept entirely.
A simple example is Bill Gates. The odds were radically better that he'd end up in the top 10% than in the bottom 50%, based on his traits and circumstances growing up. The same goes for Paul Allen, even though he came from a different economic background than Gates; his attributes, circumstances growing up and chosen professional field heavily tilted the odds toward top 10% rather than bottom 50%. You have to know enough about the person you're talking about, if you want to have some glimmer of insight at the odds in question.
What's more important for the majority is how good life is at the bottom half than the top. You're far more likely to get knocked into the bottom 10%, and especially the bottom 50%, than get into the top 10%.