Indeed there is Runway30 however the Welsh Government is also supporting the Cardiff to Anglesey route at the sum of approx £1.3m a year along with approx £800,000 for the terminal.
The Welsh Government is also supporting the North South rail link which competes with the air service however they may deem connectivity as the reason under PSO.
Without any financial backing from the Welsh Government I believe there is no chance of a Cardiff to Hawarden service taking off.
The benefits of Hawarden compared to Valley is there are likely not to be bank holiday and weekend & evening closures which could possibly hamper some business passengers.