They are legal, for now. Once crypto becomes big enough to actually affect the changes it seeks to, we will see legislation shooting it down. Turkey is just one of the first examples.
I expect stronger condemnation towards "anonymous" cryptocurrencies (Monero, Zcash et al) and making onboarding/offboarding for them more difficult, but that's about it.
I don't see that happening anymore. There's too many startups with too many smart people working in the space and a LOT more people (including the legislatures) invested in Crypto.
But, if you believe otherwise as a capital market participant, buying and holding Bitcoin is a fine play to back such a belief.
History suggests that won't last forever, but it probably won't be COIN shareholders or activist hedge funds that forces a regime change as big as that.