The sort of things I'm looking for in a loyalty programme from Easyjet are mostly "a free Easyjet Plus card" as well as fast track security everywhere and some benefit for travel companions at least some of the time - so when I travel on holiday with my partner she can board with me and sit with me without having to buy her speedy boarding. This could be a 4 times a year only, say.
The free changes look attractive, but in practice my plans rarely change from when they are booked (a week or two ahead of travel). Perhaps I am too well trained to just live with what I booked
(I travel ~60 Easyjet sectors per year).