He can borrow against that asset value for liquid cash at extremely low interest rates, so he essentially has access to at minimum 50-80% of that value. For all intents and purposes, and especially given that it would be essentially impossible for an individual to ever actually spend a trillion dollars, he has that much money.

If I own a house outright that’s worth $2 million but I only have $10 cash in the bank, it would be entirely disingenuous to say that I’m poor. It’s far more accurate to say I’m a millionaire.