How to ensure correct access across all SaaS services

Here's the problem, whenever I get onboarded to a new team, it's an endless stream or asking someone to be added to this other GHE repository, get access to a specific Jira board or be added to the correct AAD group so I can access the K8s namespaces.

SSO only makes sure I have an identity in each of these. But granting access to all the various things any team member needs requires the identity to be added to (tool specific) groups/teams/whatever. It seems all the companies large and small I have worked for so far rely on peers or managers to maintain this manually. What better options have you seen?