The major governments of the world have for some time been laying the groundwork for their own national cryptocurrencies. Does that matter? Yes, it matters a lot. Bitcoin will be a direct competitor.
Why do they do this? To remain in financial control and to stop financial crime like whitewashing of funds from happening. Is it likely to happen? Yes, the US banned holding gold privately in the 1930's. So that the US government was to be a monopoly gold holder in the US.
There is a clear danger that the US, Europe, China, Japan and others will get togheter and flat out ban and even criminalize the usage and holding of Bitcoin. Resulting in after the ban, if you are cought using and holding BTC, you would get a huge fine or jail term.
The price of Bitcoin would get killed completely, you would be looking at Bitcoin below $1000.
How likely do YOU think this scenario is? Although you might say this is only speculation, IT IS A FACT that these countries are working on cryptocurrencies of their own.
I think this will happen but it is not going to be as easy as you think, politicians are for the most part controlled by people with a lot of money and we are now seeing that institutional investors are coming to the market of cryptocurrencies, if enough of them come then they will never allow for bitcoin to be banned, they will allow regulation since that benefits them but never a ban, a ban will only be over the table once an economic crisis comes that devastates fiat currencies, but once that happens people will choose to disobey the law anyway as the only other alternative is to lose all your wealth you have worked so hard to obtain for most of your life.