Is it custodial trash? Yes. It is better than traditional custodial trash? Also yes. Why? Because you get better privacy, ability to withdraw whenever you want (via lightning) and move money between mints, etc. Every nostr user can have an address to receive zaps at INSTANTLY with zero clicks or dealing w setting up a lightning channel or node, that is powerful. There's also fedimint which is worth looking into and offers slightly different trade-offs. My knowledge is not super deep on this topic, but I've come to the conclusion that it's "better than traditional custodial services".