Thought experiment.
Option # 1
Let’s say you have 10 bitcoin and we hit 2 million in the next few years.
You’re tempted so you sell it for 20 million dollars.
After taxes you’re be left ...
Option 2: Mainly because you’ll have more bitcoin. Once Bitcoin is $10 - 50 million it probably means the dollar is in free fall and frankly it’s going to be difficult to get rid of the dollars you trade into.