Part of the problem is that android is an "other platform" in the first place. Sign in with apple is supposed to be a cross platform feature, but Apple can't be bothered to even write out some decent documentation for a platform with over 2 billion devices. Compare, for example, the Google sign in for iOS. They provide a working example project and full documentation.
If you are a developer supporting a cross platform app, you're not getting much help from Apple. That's what the article is saying: integrating this feature is going to be more work and more risk than it's worth. That's the point.
We are talking about signing in. This is one of the most fundamental features you need to have. This is not something that you just copy paste from some half baked blog post. It is amazing to me you think that's acceptable.
Have you ever actually implemented a proper sign-in process e.g. with OIDC, JWT, SSO etc ?
Because half baked blog posts is the industry standard.