Is it possible for a pure business person (non-coder) to just install GitHub Desktop on his laptop and setup up pages with custom domain and drag drop a folder of HTML and CSS content from his laptop to GitHub Desktop and the website will magically work out-of-the-box ?
In theory… maybe but you would need precise instructions.
I don’t think Desktop app is required too. One can just upload a whole folder into github.com’s repo in the browser too. I just found out that one can setup up multiple domains pointing to different subfolders of a username.github.io account : https://deanattali.com/blog/multiple-github-pages-domains/ - This is really useful for people who have a company / product website of 2-5 pages.