Custom user fields can be displayed on the user card and the user’s summary page. To display a custom field on the user card, select the ‘Show on user card?’ checkbox when you create or edit a field. To display a custom field on the user’s summary page, select the ‘Show on public profile?’ checkbox when you create or edit a field.
To display these fields on the users page, for example https://meta.discourse.org/u would require a fairly advanced customization. The fields that are displayed on the users page cannot be adjusted through site settings. If the users page is not useful for your site, you can hide it by deselecting the enable user directory Site Setting.