I want to login as a user with less rights (ie a simple contributor or reviewer) who has reported unusual behaviors I do not see myself. For example, I want to open incognito, go to an admin account feature, login as "impersonation" of a user I pick, and see the UI as they do (not as account administrator). This lets me debug and maybe report errors without needing a zoom call to see them screen share when they hit errors.
This same feature could empower your support see for themselves the bugs we must currently screen capture and video record as bugs. If we need a 24hr 'allow impersonate' I would go for that option while your support or engineers can directly see problems for themselves. This will save us the problems of capturing details when reporting the almost weekly release of bugs, ie 403 errors, logs not working, features not working as before (or ever), page load errors, resource loading error....