What is the latest estimate of global wealth, not world GNI or GDP,
but total global net assets including private property, e.g., global
balance sheet?

That's a hard question. On a global level, the only assets that count
are real assets (since every financial asset is someone else's
financial liability). If you're technically rigorous, currency is
excluded because it nets to zero like any other financial asset.

The Federal Reserve Bank of the US number is $130 trillion. Does
anyone compile data for all central banks?