The killer feature is that you can extend this with your own macros. E.g. if you want the address bar to recognize "hn " as a prefix keyword, and redirect "hn firefox address bar" to, say, Algolia — you simply create a bookmark with "Keyword": "hn" and "URL": " https://hn.algolia.com/?q=%s " (not actually a URL, don't click on it) – %s indicating where the macro parameter substitutes. Then "hn firefox address bar" ma…
This used to be baked into Chrome too but they removed it. I'm guessing to juice the Google search metrics. https://twitter.com/googlechrome/status/1504858912692084745
Still way less confusing than Firefox's UI for this though. What I like most about Chrome's implementation is how by default the search engine is linked to the main site, so I can type "yo" to visit the YouTube homepage or "yo" to search YouTube. And there's no need to manually set anything up (except to click the "activate" button now next to each site you want to the feature on, unfortunately).