Because people are discussing different things.

We need to talk more about pages vs applications, web compnents are an excellent choice for making pages more maintainable, but without support for somehow automating translion of internal state (often data in a machine suitable format produced by an API) to visual state (for human consumption where said data might be scattered or otherwise recomputed) then you do run into the "maintainability" issues as soon as the visual state needs to be updated by user updates to the more machine near data model.