I think the unfortunate truth is the simplest. Web development has long been detached from rationality. People are drawn to complexity like moths to a flame.
Not to complexity, but to abstraction. The more something is abstracted away, the more fungible "developers" become, to the eventual tune of Claude Code.
No one cares that trying to debug a modern application is as hellish as its performance, the KPI that executives go for is employment budget.
You're still left alone with i18n, auth, and pretty much anything to do with the backend, all of which the Rails of this world have you covered.
On serious projects, it feels like even Claude Code could be more efficient with simple technologies, providing near-instant build and debug. With reduced abstractions and output looking like input, it can better understand how to fix things rather than trying to guess how to manipulate framework state or injecting hacks.