Why SAML is not preferred way for SPA (Angular + WebAPi2.0) application in Okta

Questions SAML
1

Why SAML is not a preferred way for Okta integration of a Single Page application built using Angular 6 and Asp.net WebAPI 2.0.
I looked for the answers online and always found that use OpenID for Single page application.

Can anyone help me with the reasons to justify?

Thanks in advance!

2

SAML requires an out of band metadata exchange between the IdP (Okta) and the Service Provider (your app), this is not possible if you don’t have a server side component