Govts control ISPs and port based code can be blocked at ISP level. Said it many times here to crickets.
First, very unlikely any Government would even try do to this, or want to. Most leading and dominant countries (China being the exception) cherish values such as individual freedom of speech, choice, thought, expression etc. And some have such concepts constitutionally enshrined. They realize, that Bitcoin is nothing more than a medium of exchange that people, globally have collectively agreed to use, and that such creation and use of and desire for an asset is a natural evolution of technology.
Second, even less likely they would succeed in doing so. As we are seeing in China as an example, VPNs are used. Another option is for traffic to be routed through Tor. Also (again as seen in China), people simply access/buy whenever on any overseas trip outside of the jurisdiction. For many people from China, the first thing on their "shopping list" once overseas is bitcoin. They set up a wallet, get their sats, and know they will be forever accessible if they ever leave China (whereas all local assets might simply be seized, and all CCDCs simply seized or cancelled for any "wrongdoer" (including those overseas).
A government could try to ban computers, phones, and the entire usage of the internet in their country, but again very very unlikely that any modern and successful country would do this, let along be able to enforce. North Korea is probably the most successful in having done something that approaches this.
So again, for all practical intents and purposes, the FUD that a Government might "block" access to or use of Bitcoin is highly unrealistic.
Successful investors consider the likelihood of future scenarios, and then invest accordingly (as opposed to unsuccessful investors, who think up far-fetched and ridiculous scenarios and then invest accordingly...)
