Thank you so much for taking the time to write down all these details for us... really helps me understand but to be honest, all this sounds terrible. I am very surprised they let things slide that much. No excuses, despite high season - they should know better and they've been heavily booked for years. Amanzoe certainly emerged as a winner from Covid in terms of revenue... Greek was open for the most part of the pandemic and many took the chance and made Zoe their home.
I am not too familiar with the labour market in Greece in recent years, if they were suffering from the same hiring problems... but would not believe they laid off many, also seasonality is a factor here. But no excuses, all of your points are valid and this is so very disappointing to read.
I will keep the booking for now but if it's that bad, I would definitely move to FS Astir Palace.