He did this for fun, his motivation wasn't to find the cheapest way to host his content.

It's also not like you'd have to have a separate server/vserver for every such project, a very affordable vserver will run quite a lot of nginx containers. Plus I guess some people will have a vserver or something like that anyway (I have a small one to get around NAT at the ISP level), in which case it might be net-zero.

>get around NAT at the ISP level

genuinely interested in the benefits of this. care to share?

My ISP puts everyone behind some sort of NAT, which means I can't reach my home network from elsewhere since I can't open ports. They'd let me buy my own IP address for a monthly fee, but I've found that an old Pi I already had, an autossh-ed reverse shell, SSH forwarding and a cheap cloud instance work just fine for checking sensors and the like, cost less and the cloud instance has other uses, too.

I see, so NAT traversal over SSH as opposed to VPN/DDNS

I honestly don't understand where's the fun in using docker for anything.

Unless one is into masochism.

Especially to host what could be implemented as a single static HTML file.

React is compiled to static content so this could be hosted with GitHub pages too

I build static sites in Docker too. But then simply extract the built files out and upload them to any static hosting I need.

This allows me to self contain all the build tooling. And allows other developers to setup a dev environment in a few easy steps.

There's no reason that this would have to be hosted on a traditional server.

Free as in beer, yes