Musk owns stock worth billions. Stock is a liquid asset, meaning he has billions in liquid assets. The $2.6T market cap is what the public shares of MSFT are “worth.” They are owned mostly by people and orgs other than Microsoft, meaning that value is not an asset to Microsoft.

Your comment is low-effort. Don’t do that.

Market capitalization means that every share of MSFT combined at the current price is worth $2.6T. The company has $100B cash on hand. That’s actual cash and investments that could be easily converted to cash. Substantially less than $2 trillion.