The same argument. If a coordinator doesn't have the reputation to attract enough users to put enough volume/liquidity into the coordinator then it can be sybil attacked by bad actors, and essentially make it function like their own honeypot. It's not a flaw in the coordinator, I'm merely saying that low liquidity = less effective CoinJoins.
Sure, more liquidity is absolutely an advantage when defending against a Sybil attacker. The minimum input count of the round is known ahead of time,
so you can avoid choosing a coordinator that provides an inefficient/insecure service.
You're actually right! That's why, after closing zkSNACKS' coordinator, it might take some time before another coordinator will gain enough reputation for it to gain enough trust from the community, and therefore gain the liquidity to give an efficient and secure service.
I'm curious about new coordinators, do they need to bootstrap the service with their own liquidity?