PUT is idempotent, PATCH is not always. The semantics of a PATCH payload are up to the server and standards like JSON Patch (RFC 6902, https://datatracker.ietf.org/doc/html/rfc6902) allow non-idempotent operations like adding an item to a list.
In the early 00's, I used the CDs for free internet access on vacation. There was a local dialup number ~wherever you were and it was plenty fine for email and browsing the web of the time, and as long as you cancelled within a month, it didn't cost a cent.
Quora is not limited to technical Q&A. Also, it allows people to put things like "3x SEO EXPERT CHIEF VP FOUNDER" next to their name. Lesser Q&A sites (and BBSes in general) do not implement this feature.