why not compare web dev to where desktop was 20 years ago. The question from the user perspective is not whether this or that type of development is getting better, but whether software offers us new affordances today, which it does, but most of them rely on server-side processing and cloud data.

I think you bring up a great example. Which kind of application has gotten better than its past desktop counterparts because of the improvements in javascript? (counterexample: we lost Flash)