I don't understand why people argue for a limit on wealth - the line of reasoning, when reasoned out, concludes with a majority of people having the exact same amount of wealth.

How so?

Well, suppose we say, nobody should be a trillionaire - is this an arbitrary number, or is it aimed at the richest person? Clearly, the latter. Now if we carried this out, now there are billionaires remaining. Well, nobody should be a billionaire, one might say. Most will agree. So the wealth of billionaires is taken away, and redistributed evenly.

This will continue, with the majority of people below the average wealth level, demanding a more equal playing field. You can see how it ends