Do you use them (or know of anyone using them) for anything interesting or novel?
Approach it from the opposite side - do you have a use case or a problem that might be solved with either of these tools? Then try them out and see if they help. If you dont, then who cares about the complicated things that can be done with Airtable or Sheets, none of that is relevant to you.
Imagine your marketing department needs to create a list of websites that have run their PR campaign. They can keep that data in Airtable or Google Sheets.
The developer then displays on a simple webpage in a card like https://nomadlist.com
There are sites like https://sheet2site.com & https://table2site.com that automate this feature.
You can also create custom apps with it. https://pory.io/ automates it.
These aren't templates in the strict sense. Rather hundreds of real examples of things other people have built with Airtable and are now not only viewable, but free for anyone to copy and use. Scrolling through these really gave me an idea of just how versatile Airtable itself could be and also helped me get a better sense of where I might start with the product for the business use case I was looking to solve.
https://dronahq.com/admin-panel-spreadsheet-to-app/ or refer https://www.dronahq.com/how-to-build-an-admin-panel-and-dash...
The novel ways I've seen them used are around the development of Apps / internal tools, using low code builders like Budibase