Earlier quoted context omitted.
Any simple definition is distorted, inevitably. Income, consumption or utility have a case. That said, wealth by this definition is most relevant in certain contexts. If you're worried about political consequences, for example. When the majority of property-wealth belongs to a small minority the majority have less reason to preserve property rights, for example.
The availability of credit will allow those that are asset poor but with reasonable earnings potential to compete for resources fairly. There are of course very serious implications when, for example, asset bubbles and unfunded state liabilities will create unfairness between generations. That's an example of real inequality. There are many other forms of real inequality. Fake inequality is when two people with compa…
But, I think wealth (above definition) may be important as a stand alone. Many of the political implications of wealth disparity have more to do with current wealth than income, for example.
I do think you have a point though, as I said. Some wealth disparity is a matter of age, for example. But the disparities we have and those we project are very large. They may overstate disparities in income and consumption taken alone, but I don't think it's more clear headed to dismiss them outright. They do indicate a real and growing disparity.