RyanAir is about exploiting consumers, with bait-and-switch and shitty terms and conditions.
RISC-V's modularity is about giving choice to hardware designers, so they can pick and choose just those features that their solution needs, and even allow for custom extensions.
RISC-V's modularity is for academia. 1) for education, where students learn/use/work on simple processors, 2) for research in new types of hardware and extensions, where ease of implementation or ease of creating a custom extension is important.