Yes I realise that, but doesn't it invoke trust issues? Isn't it bad from a "decentralisation" perspective? Besides, many people (me included) would prefer to not do coinjoins instead of doing coinjoins where a specific entity could see and potentially track everything. To be fair, I don't know what these co-ordinators do internally, but I guess they could keep logs etc.
The WabiSabi coinjoin protocol is trustless. You do not share any trackable information with coordinators, so it doesn't matter what they do internally. Clients use a new Tor address for every interaction so that activity can't be linked together.
This assumption weakens if the coordinator server isn't stable: Repetitive connections to the input registration "lobby" without ever actually completing a round will eventually leak metadata over time.