Aer Lingus is a slightly weird case; they have essentially become a budget airline (at least for their European business) to compete with Ryanair, but they haven't yet gotten around to adopting most of the dark patterns.
Their trans-Atlantic flights are ok and cheap relative to United (out of IAD, to points in continental Europe). Their EU flights are a noticeable step down.
IIRC Aer Lingus could already be described like that 10-15 years ago. I remember it as cheap but decent.
I don't think it's a weird case to compare two budget airlines to demonstrate why I think one is better than the other.