Problem/Motivation
Umami has been very good for demonstrating what's possible to do with Drupal core plus a theme and no contrib modules since it was added to Drupal 8.
Parts of it have fallen behind with the state of core, although that's gradually being worked on with #3426579: Update parts of Umami that are falling behind.
There's also #3365143: Model core's Umami install profile as recipes to convert it to a recipe.
However now that Drupal CMS exists, it's less clear to me what the role of Umami is.
Drupal CMS's installer doesn't provide the option to install Umami, but is also the recommended download for new Drupal users and evaluators. It will also at some point include a default content recipe. So for me Umami is currently in the 'wrong place' e.g. it doesn't really make sense in core any more, it might make sense as an example site that you could build with Drupal CMS - at least once Experience Builder/Theme Builder are included and could reduce some of the custom theming.