There's a very large unclaimed bounty for breaking Monero's privacy.
And those two are the tip of the iceberg. Check out Dero for one that's doing smart contracts with homomorphic encryption.
The future of privacy coins, based on these examples, is simply that they work, and will do so as long as the encryption mechanisms do. So we are presented with a question of which applications benefit from public vs private chains.
I don't doubt that anonymous transactions are possible, I want to know if they're actually accomplishing what this person is claiming. They've had plenty of time to do so.
I think it's unquestionable that privacy is generally helpful to victims (or rather, the victimized.)
I think what he might be referring to in particular is that the traditional blockchain and even financial system at large is incapable of protecting at-risk individuals (eg activists), as the former is subject to chain analysis and the latter is subject to the whims of whichever regime has taken power.
There's at least some evidence that Monero is resistant to US government sanctions. They tried to sanction a wallet and ended up sanctioning a transaction hash.
The argument that transparency can lead to coercion can be quite convincing — privacy technologies can give power to victims.