It’s also not a new problem to Gatwick, by virtue of the fact that it’s always been an airport where the majority of flights are with based aircraft that start and end the day there. There will always be not enough gates in the morning and too many during the day.
Even back to pre-EZY days in 2002/3, when the airport was full of the larger 757/767s that would leave for the Med every morning. At least 8 different charter airlines were based in Gatwick, which would’ve added up to a fairly similar number as EZY have today. Perhaps a little less noticeable because many of the charter airlines back in those days would come in at 2230 and go out again an hour later. Alas, the arrival of EZY and EU261 largely put a stop to the round the clock operation. Nostalgia.