But if you have 16,000 of anything, why are you using a static site? Surely the access patterns are long tail and you need to build more often than most pages are even accessed.
Surely there's a CPU/disk trade off at some point. Static pages are much larger (less likely in memory) and would cause disk reads much sooner than the same files being generated dynamically. Of course wordpress isn't known for it's efficiency so the static page preference is probably quite high.
there is a big difference in the cost of static hosting and CDN (think Cloudfront / S3) for static stuff and running an active piece of hardware for static stuff that doesn't change. Like orders of magnitude. Sure for small sites it's not that much but it's still orders of magnitude.
also the answer to a large number of my interview questions ends up being figuring out how you can just effeciently serve the stuff from a CDN/Blob Storage. You can scale the crap out of this for quite cheap.
If the final result is 500k of HTML, a dynamic website is doing a LOT more work to return that 500k than a static website. Assuming you get more traffic than you have pages/generated.
Admittedly in this case I'm mostly just trying to push Gatsby to it's limits. For a photography site, there ends up being very little overhead with a static site (if you can do incremental builds). I also explored NextJS (SSR) and just making a good old SPA, but decided to go with Gatsby because at the end of the day, a distinct majority of the storage cost is just the raw images. I think Gatsby ends up making the most sense because you get to take advantage of a CDn for caching (most don't like being used just as an asset cache) and I can just leave it there without worrying about a server.