I don't think if government takes over cryptocurrency or cex exchanges that people will patronize it more than Dex. In fact it appears that Dex is not very much in use now or popular but if the government come up with policy to acquire cex then you will see more people living cex to patronize Dex, this is because of trust. Government is not trusted with the people, people already avoid KYC because of the believe that government could have them if they want so to have cex under government control directly, more people won't patronize cex. They would rather go with Dex if that happens.