No, it’s an oversimplification to say that Netlify requires an SSG structure. In your original post you indicated that you want to update and maintain your site using Netlify CMS, hence my recommendation that you start with one of the one-click SSG installations. There are other ways of generating a static site that are perfect for Netlify hosting, but which are not maintainable via the Netlify CMS.
One-click installs don’t mean you’re not learning anything. They simplify ONE of the steps involved, but there are still plenty of other steps – and plenty of learning necessary to get them working on anything but the most basic level.
To give one example, the approach of each of the SSGs is slightly different, and there may be some that don’t fit what you’re trying to do. With one-click installs, you can more quickly evaluate the various platforms, as opposed to having to learn each one from the ground up and then starting all over again with the next one, and so on until you find one that’s right for you.