Scalability of Keycloak Access Mgmt system for Self-care users

Question

I am currently evaluating Keycloak as one of IdM and Access Management system. My client is Telecom Service Provider and have a requirement to support the Self-care users with expected volume of 60 to 80 million users with approximately 2000 to 3000 login requests per second. I want to use Keycloak to Authenticate and Authorize (RBAC) end users using OpenID Connect.

I tried searching for information on Keycloak scalability with Relational DB or Directory Services and the performance, however, I did not find much information about the same. The Keycloak documentation talks about Clustering feature but the stats are not given.

Can someone please help me as per your experience with Keycloak performance and scalability to support the Self-care users of 60 to 80 million volume?

Also, kindly suggest if I should consider any other IdM and Access Management system with above requirement of scalability for my evaluation.

Thanks and Regards, Kedar