NGNUSD chart shows that over the past decade, NGN has lost 90% of its value compared to USD. I don't think this is a result of the emergence of crypto in Nigeria. In NGN's devaluation scandal, crypto is innocent!
Hihi, not really, it can also act like an intermediary for this, much like gold has in the past!
For example somebody wants to buy Bitcoin with Nairas, but since Bitcoin is valued in dollars and it is not something that you produce locally, much like gold in most of the times you buy it from somebody who is not really wanting your currencies and it changes it immediately into another, basically exacerbating the demand for $ and increasing the offer for Naira's also.
So for every $million of crypto purchases there will be one million of $ needed and the equivalent of $1million nairas on the market but with different demand, which would devalue the naira, then with he next batch more naira's less $ to trade for and so on and on and on!
Much like how the Argentinian peso is devaluating as people buy $!
Of course the scale at which happens when compared to the other ways the naira is dragged down by failing exports and costly imports is just below the level of margin error but if every citizen would decide tomorrow to buy bitcoin wish all it's wage, then yeah, it will be like an instant collapse.