I tried and it seems it's Keycloak with an easy UX, a lot less features, and you're limited to only one realm.

In case you're looking for multi-tenancy with self-service, maybe try out https://github.com/zitadel/zitadel Would be glad to get your thoughts on the platform. (discl: I work for ZITADEL.

We started as for customer identity, which means the current version is for the apps that have external customers, e.g. an online store. We’ll constantly iterate to fit more scenarios.