This is only true if you think in black and white. Liquid for example (this is who you mean, right?) is a federated model and therefore a security model with trust distributed across multiple signers. It inherits much of the security and trust model of the base chain.

Cashu, however is a single point of custody. Not only that, but the issuer can melt (or claw back) the value of issued tokens at any time. They can also just close their lightning channels and mint and steal all the value. So, though it gains fantastic privacy, this implimentation completely tosses out censorship resistance, and requires complete trust in the mint.

Doing this in Liquid would be difficult and would require collusion amongst several signers.

I strive NOT to think is black and white paradigms. So I CAN see value in both of these "bitcoin bank" (see an early post on the BCT forms from Hal Finney on this topic) implementations, and am all in favor of their development.

But the claim made above is entirely false and possibly dishonest.