To be sustainable Wizz air and Ryanair simply have to fill their aeroplanes at the best yield they can so routes do chop and change a lot. In a pandemic the need to do that is even greater.
Easy Jet do not mange to achieve the low cost base of either and therefore look towards customer retention to a larger extent, they thus change things more gradually.
I would hope customers know this is likely now and accept that to get cheaper travel there are some strings attached.