Here's a potentially unpopular opinion, no service needs a frequency higher than 30 minutes.
The only reasons to have a higher frequency is to increase capacity, or if it's providing a direct link between two interchanges ie. between Metrocentre and Gateshead or Newcastle.
IMO, a single decker operation with a frequency higher than 30 minutes is a waste, it should be upgraded to a decker before they increase the frequency. Obviously in cases like the 49 where there's a low bridge on the route I can make exceptions. But other than that, I can't see any valid reason.
RE: September 2022 Service Changes