This looks like written by ChatGPT, and it is in many ways straight up off-topic or wrong.
Origin/Era: yeah, duh. That was already stated in the question.
Architecture: It doesn’t actually show any differences, it just doesn’t talk about different parts of the architecture. Usenet is also federated and Fediverse instances also don’t store all messages.
Content structure: This is the closest to an actual answer. But from what it seems, the default use case of the Usenet is identical to Lemmy.
Protocols: Stated in the question. NNTP is also federated.
Moderation: This is straight-up wrong. There are moderated and unmoderated newsgroups, same as there are moderated and unmoderated instances/communities on the fediverse.
Modern Relevance: This whole section is irrelevant to the question.