I agree that the initial setup is a bit complex. And at the time of writing, I could not find anything better. But once I set it up, it's quite friction-less and low maintenance so I didn't look further.
However, if you have pointer to a better solution, appreciate a link. Always looking to simplify.
Not saying you should change it if it's working, and I don't have a ready-made tutorial, but assuming you only need to serve static files I would:
(1) upload the files to an S3 bucket (GCS or Cloudflare R2 may also work, haven't tried);
(2) point Cloudflare at the bucket via their Cloud Connector;
(3) turn on Cloudflare Access.
For anyone who might find this interesting, I wanted a static site knowledge base but private: https://chanux.me/blog/post/static-site-with-auth/
I host this with GCP and stay within free tier
And how I deploy a similar thing with GCS/Cloud build etc is covered here https://chanux.me/blog/post/automate-static-site-publishing-...