Also noticed this recently - whats driving this? Non-developers looking to prototype or build actual products without developer involvement? Democratisation of technology?
I would say ease of use and cost. A friend of mine has been using Google Sheets for years to power some small bits of data on his website. Maintaining and running his site costs nothing but the domain since he uses Netlify for CI w/Github and hosting with Google Sheets for dynamic data.
Very easy to set up a small database that non-tech people can also access. It's also a very light-weight way to implement a CMS with users and version control etc.
His "credits" section and song list uses Google Sheets: https://www.pontusrufelt.com