PUT, DELETE, etc were part of HTTP/1.1. The WorldWideWeb browser (later called Nexus) was created during the time of HTTP 0.9 (or rather the versionless HTTP).

I spoke to a few of the people involved in the original 1990s project and one big issue was authentication into servers was way too complex.

The simulation (I wrote the JavaScript for it), writes to local browser storage (IndexedDB), the original WorldWideWeb would write to disk (networked or local).