Payment Channels with central hub

Yes,
I’m aware of, but not every channel need to serve same purpose.
Imagine service like ‘eBay’ using payment channels with central hub (managed by him)
You can enjoy fast cheap transactions and You do not mind that ebay knows what and when and from who You where buying. Actually You might even prefer it since that gives ‘eBay’ opportunity to build some insurance for buyers system on top.