Consider the following:

Governments close down:

- All or nearly all major exchanges
- All or nearly all major online market places using Bitcoin or some other crypto they want to target, including those on the darknet (on which LE is quite succesfull as of late)
- Outlaw Bitcoin (or again, some other crypto they want to target) transactions altogether, and actively police shops and companies that openly accept it.

You do not consider that this scenario 'might be problematic'? As said thousands of times before: nearly no one uses Bitcoin in the present. The percentage of the population that heard of it is (very) small as well. Without mainstream backing this will be a massive hurdle, if not a fatal one, as by far most people in society are not even interested in the ideological goals of hardcore Bitcoiners. And those people will be reading newspapers as well, including those that constantly vomit out negative stories about it.

Whatever happens, governments can effectively crack down on Bitcoin and other crypto if they'd like. There is no need to take down the network in order to make that possible.