Searchkit doesn't remove its tables when you uninstall civi
This isn't specific to search kit - the more general issue is that extensions don't run their uninstall code when civi is uninstalled - but search kit is the first extension that gets installed along with core and is enabled by default and has its own db tables and those tables are named civicrm_something
.
So I don't know if I'd call it a bug, but it can cause some confusion when trying to re-install civi after uninstalling. In particular because https://github.com/civicrm/civicrm-core/blob/4d167cf85621e257b43752e6eee7c87abe5d69c2/setup/plugins/checkInstalled/CheckInstalledDatabase.civi-setup.php#L26 thinks civi is already installed and it's not obvious to the user why, especially if using the civicrm/setup screen which just keeps redirecting to the "already installed" page no matter what you do.
Normally core tables get cleaned up when you uninstall civicrm because they're in sql/civicrm_drop.mysql, which is generated from the xml/schema files. Here, search kit is both core and not core, but its tables aren't listed in drop.mysql.
Perhaps civi can try to uninstall all the extensions first before uninstalling itself?