In terms of passenger numbers at least Newcastle to Berlin did work. Unfortunately EasyJet then moved the flights till late in the day so they were unattractive to business users. Plus it started cancelling a lot of flights during a previous bout of crew shortages. Numbers dropped mainly because of what EasyJet was doing rather than an inherent lack of demand. Munich with HLX did not work particularly well, but only ran for a few months and didn't have much marketing.