For sure, there are a bunch of reasons not to use Google Sheets. For this, it's just an easy, free, and temp way to get a new site up without needing to setup a backend.
It's not really a hard requirement for me to get off Google though, just to avoid using their ad-tech. For privacy concerns, using Google Sheets isn't all that different from using MySQL on Google Cloud, etc.
When looking at solutions, did you consider using a private git repo?
On that thought, you could potentially hook it up to Google Sheets or editors that integrate with remote git repos. Skipping 3rd party hosts, you could host your own git server for cheap too.
Awesome project nonetheless! I'm a hypocrite still using GA but want to move off of it this year, so reading your solution has me thinking about my own.
It's not really a hard requirement for me to get off Google though, just to avoid using their ad-tech. For privacy concerns, using Google Sheets isn't all that different from using MySQL on Google Cloud, etc.