But if they are not controlled by the banks but belong to you, it gets much safer and better.
It doesn't guarantee security if you don't have sufficient security knowledge.
Bitcoin is not dependent on anything,
Bitcoin depends on infrastructure: electricity, internet and activities: mining, and nodes. And actually the government can influence some of these components.
but I think if all governments accepted Bitcoin, Bitcoin could go far. People consider cryptocurrency as one of the sources of income.
This requires some preparation, especially in terms of crime risk protection. Bitcoin cannot simply become a source of income without "business" activity, including deception.