We love Nostr as a publishing platform that offers unparalleled censorship resistance. But NIP44 does NOT provide most of the important qualities of e2e encryption:

- break-in recovery.

- repudiation (deniability).

- visibility of connection graph to observers.

- fixed message sizes (although it can be provided by the specific app)

- resistance to Shore algorithm (PQ encryption).

It's unclear whether it provides forward secrecy, but the spec implies that it does not - I might be wrong here.