Judging by https://github.com/mawww/golf kakoune is capable of completing the majority of the same editing tasks as vim in a very similar amount of keystrokes. The main advantage of multiple selections is that you can see which text you will operate on ahead of time, rather than having to first select which operation you want (delete/yank/change/etc) and then which text it will affect. I think pointing out that vim's selections aren't as capable as kakoune's is a fair response, and saying that you can accomplish similar things without selections is a bit of a deflection.
Golfing is not the best representation of day to day text editing, but I must say that optimal Kakoune solutions are usually pretty close to normal workflow.