>>Borrowing to do what? Sit on the money borrowed?
>>Otherwise, see above.

Presumably we agree that Capital Gains and therefore Capital Gains Taxes only occur when you sell. My point about assets that are held in perpetuity is that this tax can be deferred forever. In the meantime the asset can be borrowed against to purchase more assets to be treated the same way. Thus wealth begets wealth without paying a bean to the taxman. This is how wealth concentration happens once you reach the upper elechons, including for people who don't pay any income tax at all- because they don't have a job.