But most of the bans are not retrospective. If government bans bitcoin today, it doesn't mean I will be prosecuted because government can track the trade I made yesterday. So unlike gold, I have a clear working plan if bitcoin gets banned. I can immediately send all my bitcoins into hiding using mixers. I can even sell them in disguise. All these features weren't present in case of gold so government could easily locate the person if he tried to sell gold in market. With bitcoins there isn't such problem.
Partially true! Even if a government bans bitcoin today, they will give you a certain period of time to get out of it. Nowadays a government doesn't really likes to take arbitrary decisions. So you will definitely get an exit period during which you can sell off your bitcoins to the open market.
But yes, gold didn't have the technical advantages like bitcoin has today. You can definitely use mixers to hide the trail of the bitcoin and store in anonymously. Gold was physical and it has its own associated risks of handling! Similarly bitcoin has it own technical advantages!