I mean, I like a browsable GUI where I can look at a project in more or less detail, and without actually spending disk space.

Github is a way of quickly getting some indication that software is legit before you install it, because you can see at a glance various ways others have interacted with it, and potentially look into things further. If it's on Github the code is probably at least published, which is another sign of not being sketchy, so it's a good thing to be able to append to a web search. I also like that it's easier to find info about how to install software from Github than from some self published website for that particular software, because the information is generally going to be in the same place and use the same conventions every time.

If you're only writing code for yourself, Git by itself would be fine, but there's definitely a need for something that is basically a sort of social media for software.