I recently rewrote a website/small backend API for a non-profit organization. I could've gone with a serverless architecture for our forms handling API and reduced spending to nearly the free tier, but I had no good way to protect against a scenario like this. There was just not good enough documentation about how to completely cut off spending in the scenario of an attack, and I wasn't comfortable leaving the organization open to a cost attack like this.

So we're using Github Pages for static hosting and a $5 box from OVH now. Unmetered bandwidth, plenty resources for our purposes. Cheap enough, and we will never, EVER, have to worry about an attack like this. Well worth it imo.

Imo, serverless is great for internal jobs where you can control spending. For public facing things, you have to be a lot more careful.