I've flown with EasyJet sometime ago, and their customer service (telephone/email support) was miles ahead of AirAsia. I had experienced minor delays with both. However, Easyjet never asked me trivia questions before boarding a plane. From the 6-7 times I'd flown with Airasia since 2015, never had I experienced such incompetence as the last two times. I can clearly sense that the service has deteriorated. e.g. gawping in to Smartphone boarding pass, procedure to follow when customer has new passport.

Prices are attractive. Actually, usually much better than their rivals. Perhaps that's the problem. Maybe they can afford to cut a few corners. (e.g. with staff training). Because some (most?) customers will take decision to fly with them just based on price or customers have somewhat low expectations of what to expect.