If that value is recognized in a beneficial way (such as unlocking loans against it or using it as collateral at a specific recognized amount of value) it should be taxed at the point of value recognition for the amount of benefit recognized.

Most income for high earning tech workers is in stocks and share value.

We can tax stock grants at 100%

You can also tax stocks yearly at a fixed rate, e.g. 2%.

You can also tax stocks yearly at a fixed rate, e.g. 100%.

Nope, 2% because they grow by 6% on average for the last 30 years.

If you dont have any disposible income then you wont have any investments to grow in value.