Liverpool was only relevant when Manchester spurned the low cost market believing the future was legacy.
Eventually, and to be fair with a degree of hindsight Manchester capitulated to the low cost market and RYR and EZY opened up over there.
Whilst they retain a degree of interest they are in a win - win situation, they really want services Ex Manchester and one base, two bases 40minutes apart is a nonsense BUT crucially the additional cost of running two bases is offset presumably by savings elsewhere. By retaining a Liverpool base they can play one off against the other in terms of cost!
The passengers they serve are driven by price so Manchester and Liverpool are in effect both "local", regardless of where the pax originate, geography does not really matter so they attract same clientele.
In terms of services to a hub, why would anybody start services ex Liverpool when you can be in Manchester in less than an hour and have multiple choices ?