No, not anything is bad for bitcoin. I am a real example: I still use cowboy credits on SN ! A centralized custodial service like SN wallet filled with CCs is not bad for Bitcoin, as many think. If you use it for a specific thing, is OK. I could say that is beneficial for me because I do not have to spend my sats on SN. I got more sats in rewards (this is a flaw in SN system) without depositing / buying any CC.

Now comes the important question: have SN an evil plan with the CCs ? I don't think so and will be useless if they will have one.

Some centralized custodial services are bad and some are good and even could add some new good features out of bitcoin network. Important thing is that people can choose wisely and well informed.

Another example of a good centralized service: hosted channels. And HC are also open source and anybody can run it. Many noobs don't even know what they are. But hosted channels could fix a lot of issues for noobs, and even adding more privacy.