I've never bought food or drink aboard a European LCC. Mostly because UK airports tend to have decent sandwich shops (Pret a Manger, for example), where the quality is always better, for the same price.

What Ryanair excels at is cutting costs to the bone, and serving obscure routes. If I wanted to fly from London to Rheims or Haugesund, they're the only option, and a lot better than changing or using ground transport. In terms of prices, if you get the ultra-cheap fares (which is not a given with short notice or weekend travel), then they're a real bargain.

I can't see Ryanair significantly changing. What I feel they should do, though, is be a little more up-front about what their service is. There's a misconception that LCCs are just airlines that don't serve food onboard. Oh, there's so many more savings you can make, and they do.

If US LCCs can learn from them, it's that you can make fares cheaper by flying to small, barely-used airports, and providing onward transport (at a cost) to near-ish cities. This certainly seems to serve them well.