Even without anonymity, it raises the cost for the government to enforce broad restrictions, because the chokepoints—which are intermediaries like financial institutions—are gone.

In any case, anonymity is a gradient. It's a question of how much resources a state has to expend to track a user, and that value can be increased with better privacy technology, so that the state has to eschew broad-based restrictions on mutually voluntary interactions and focus its investigative resources on only the most dangerous actors, who engage in genuinely predatory behavior (murderers, thieves, etc).