There's a searchbar, and the amount of content you search through is far more than you could do with clientside search.
Definitely not just static content.
It's Vercel, it's their business model. They have all the minnows eating for free, and then once you pass a threshold, you're a whale with a whale–sized bill.
That's a good question. As someone bootstraping a few projects on Vercel this post has me looking over at the pricing sheet more closely.
Bandwith costs
It would be $0 if they spent 10 minutes just throwing Cloudflare CDN in front. They don't even need to move off Vercel.
Tech bros and VCs need to eat, that's how.
There is still a helluva lot of data to transfer to the client, I'm sure it's being stored somewhere.
And with the entire world perusing this archive, I'm sure the costs will be very high, regardless of provider.