Well, actually, I am a tax professional, so I have been getting quite a few questions about the tax consequences of crypto transactions. The problem is that things are still in flux and unclear, in the US anyway.
I think they kind of like it that way, because TPTB can bully people into overpaying, just to try to protect themselves. That's a problem when they can adjust and change the rules as they go.
when you turn your ctypto into dollars and send them to a physical bank, you pay the transaction fee. There's your taxing. The government does not control that money if you can always transfer them abroad.