Occasionally I'll come across a claim that Historical Figure A was fabulously wealthy in their time, and by today's standards would have an estimated net worth of X dollars. I can accept this if the currency they used is still in use today, but it seems very questionable to do this in other cases, particularly for ancient historical figures, given the wildly differing value of things across place and time. The most notable example is Mansa Musa, who I've repeatedly heard was the richest man in history (see example: https://www.bbc.com/news/world-africa-47379458). How would a historian even go about measuring such a thing? In the case of Mansa Musa, since so much of his wealth was in gold, is it just a process of estimating how much gold he had and converting it to USD by the modern rate. If so, that seems like a poor representation of how Mansa's wealth would have been viewed at the time. I mean, for some peoples wealth was measured in cows or pigs, and gold would have had little value right? So is there any attempt to understand their wealth relative to the time/place in which they lived? Do historians actually make an attempt to convert ancient wealth to USD (or other), or is that just a pop-history thing that non-historian writers do? Even if that's the case, I'm curious about how wealth is assessed in history. Help a layperson out please?

Thanks