For sure some auth providers will be compromised at some point in the future, but there are literally thousands (tens of thousands?) of examples of self managed identity management being compromised. How many Auth0 or AWS Cognito service compromises have there been?
To your point about availability, AWS, GCP and Azure all have managed authentication services, that are fundamental to their platforms. I highly doubt they are going anywhere. I have yet to have an Cognito outage in three years.
To your point about availability, AWS, GCP and Azure all have managed authentication services, that are fundamental to their platforms. I highly doubt they are going anywhere. I have yet to have an Cognito outage in three years.