The government wouldn't ban exchanges totally, but they would always fight it because they want to control everything and whatever they don't have total control over, they fight and tax greatly tho get a lion share from it's proceeds and that's why some exchanges are discontinuing services to Nigerians.
Crypto world is still evolving and any good innovation is always faced with challenges in the early days, until it stabilizes. If crypto was a bad one, government could've wiped it out a long time ago, but things will continue getting better with time as the Crypto industry keeps reaching better maturity and standardized in the nearest future
I was strolling through my X feed and timeline and I saw some statistics of Nigerians that participated in Dogs airdrop and I was shock that Nigerian population was more 30% from those figures, I'm not sure how genuine that data were but we seem to be everywhere right now in crypto space, everyone here now want to be part of crypto and all is because the government has failed to help people in their own way of job of opportunities for the masses.
Just yesterday, I saw a news on Nairametrics about Nigeria Security exchange commission trying to work with the crypto space and trying to regulate the space by September which is next month and all I say that the Nigerian government is greedy and doesn't care about anyone but only themselves. They seems to have started collecting tax from Kucoin, maybe they will spread that very soon to other exchanges for their own benefits. They don't know anything than tax and tax.