GitHub topic tags. How to use them?

I have recently discovered that GitHub topic tags seem like a way to find interesting projects. I’ve not yet located the way find all of the available tags, but if I find a project with an interesting tag, clicking on it will often load a page or more full of other similar projects. Unfortunately, many of them seem to be projects, like many of mine, which are just place holders, or fizzled out efforts which consist of mostly dead links.

Has anyone mastered the technique of finding the front door to the tags system, or is it not meant to be accessed in anything but a relative comparison manner?