Clarification related to JIT for EDLP

Can someone help clarify how JIT actually works and in which scenario we should enable JIT.

The Microsoft documentation is very differently from what I’m observing during hands-on testing.

I enabled JIT for a specific user (only 1 user). For that user, no JIT toast notifications appear for stale files when performing EDLP activities such as copying to a network share, etc. However, for all other users even though JIT is not enabled for them their events are still being captured in Activity Explorer.

See SS below.