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.
You don't have to trust coordinators, there's no reputation required.
I'm curious about new coordinators, they do need to bootstrap the service with their own liquidity, no?
No. Coinjoins are made of user inputs.