cashu requires trusted third parties called mints. that's the architectural back-step that i am referring to. it's a lazy regression because of the problem of lightning developers dropping the ball. really, it's regressive. chaum invented blinded signature certificates that can be verified without decryption in 1983. they didn't get wide use because you could just use a bank instead. they are a regression away from the key innovation of bitcoin, that is explained away as a lazy dodge from someone actually doing something about making lightning work better.