I like the idea of having a git backend for site data, but in the case of the author: why not just use a regular host?
There are some pay-for-what-you-use hosts (e.g. https://www.nearlyfreespeech.net/).
Not to mention, while some have mentioned that you could create a github page, does that mean you'd have to create a separate repo for every page? (Not sure how github pages work at that level). This solution would allow for a single repo that holds all the sites - whereas not polluting your repo space.
I think this solution is for a particular niche of devs who control N number of domains - who want minimal maintenance and most importantly - no cost. ;)
Yes, I should write more.