Earlier quoted context omitted.
Sure it is, this problem has been solved for a long time: SCIM. Any modern idp should support SCIM and if the app doesn’t I’d question using it at all.
SCIM adoption isn't near where it needs to be. I guess yeah, this is the correct answer. We live in a world where SSO is considered an enterprise feature, I hope one day that it's considered default.
If you're building an app and need to add SCIM, check out WorkOS. My email is in my profile to chat.
More info -> https://workos.com/directory-sync