> If you’re using Webpack you can emit chunks by their content hash

You’re talking about this in terms of chunks of JavaScript, but static asset caching is something you should be doing for all static assets, not just JavaScript. Whenever I’ve seen somebody use Webpack content hashing for this, they’ve done it for JavaScript and CSS and forgot about basically every other type of file. And also, now you are tied to only referencing those assets via JavaScript because you have to get the URLs from Webpack, whereas with a URL prefix you can just use relative URLs which work in other contexts as well.