Actually, OpenID Connect is an SSO product. Whilst it can be used to federate your auth to other providers, you're probably thinking of OpenID, which is "social login".
No, parent commenter is correct: OpenIDConnect is an extension protocol that adds a user-authentication (user metadata) layer on top of OAuth 2, which is a bare authorization protocol (access tokens are opaque and don't say anything about the user).
Besides the similar names, OpenIDConnect has virtually nothing to do with the older OpenID protocols. Old-style OpenID has been deprecated and removed by almost all web properties today (e.g. https://meta.stackexchange.com/questions/307647/support-for-...)
iiuc, the complaint is still valid -- it's just that OIDC is what causes the attributes to be in the flow, not OAuth that causes the attributes to be in the flow.
