In the absence of a stable government backed currency it seems cryptocurrency could have some value. However, cryptocurrency is also unstable. You are speculating that holding crypto will be better over some period of time than any alternative value store you can access. That may well be true, but seems like that depends on what other options you have access to and would require more rigorous analysis of the tradeoffs. For example, if you were to say “crypto is a better currency than eggs” [1], that seems likely, but eggs don’t require internet access and specialized knowledge of a particular technology.
It sounds like it falls mostly under illegal transactions because you are using crypto for something that would otherwise be illegal (avoiding capital controls). Is it technically illegal? I don’t know. Is it ethically wrong? I guess not directly. However, I imagine there are also a lot of nefarious reasons somebody might want to avoid capital controls which crypto could also help facilitate.
It's illegal to buy dollars but not assets that track the USD dollar. Buying DAI is legal for the same reason buying USD denominated bonds is legal, they are not dollars and you are not taking them from the central bank.
And either way I don't think grouping "criminal transactions" with "stuff that's illegal in X country" is fair. At many points in history governments outlawed things that are very wrong (e.g. nazi germany) Just because someone doesn't want to succumb to corrupt institutions doesn't mean he/she is a bad guy.
[1] https://www.economist.com/finance-and-economics/2018/07/19/w...