I notice DUB goes to 1 daily on a Saturday on both Aer Lingus and Ryanair. Will be using the morning SAT Aer Lingus flight too, but does demand really fall so short on a Saturday?
Also, interestingly enough, on my last trip to Newcastle, there was a Hen Party on my return flight to Dublin, having their hen IN Dublin!
EI have never operated a second Saturday service but overall they are operating 16 weekly (+1 weekly on last winter) with x 3 Su (+1), Mo, Fr.
Both weekends flights now depart DUB at 08.15 and 08.30 (same lather LBA as well) and not the usual 06.00-07.00 service. Could be many reasons for this and not just lack of demand.