The real killer for me has been the fact that the keywords or bangs aren’t tied to a single platform/browser. I set them up once and they are available on my iPhone & iPad & 4 different browsers on the mac. Add this the fact that if you set Kagi as the search engine, you can perform all of these from the address bar already.
I have 10-20 keywords set up in Firefox for example. It works in chrome too.
But maybe I'm missing some use case for kagi bangs...