At Admin Panel -> Settings -> Switches, the "member status area in topic details" switch controls whether block of member details is shown on the right side of the topic details page. Some people like having all this information there, other people consider it annoying clutter that's duplicating what's already on the member profile page, so it's up to you whether to show it.

Note that the member status block only shows on the details pages of topics which are owned by a member, not those submitted by guests.

Note that the member status area is automatically hidden on screens with narrow widths where it won't fit well.