I'm not going to make assumptions like this, so bitcoin could exist in the next 100 years or maybe it will be replaced in the next 10 - 20 years.

This is a risk, even none of us are brave enough to guarantee that bitcoin will survive another 20 years. Governments can prevent you from using bitcoin at any time even though you are currently free to spend them anywhere. If you believe in the potential of bitcoin, then you still have to consider the risk of loss. But anyway, I don't expect the government to ban bitcoin permanently, shut down all exchange services or anything in the short, medium or long term. It is possible for governments to consider bitcoin as profitable in the future regardless of their current perception.