To me they are much better than browser/electron/native gui because they are light on resources, very predictable, portable and honestly they get the job done. I used k8s Lens and it gave the impression of being efficient because of the high density of information, but I haven't felt like I downgraded when I moved to k9s, and now I can manage my clusters, develop their charts using neovim and browse the web without getting dangerously close to filling 16GB of ram. Before with Lens, Pycharm and a browser that would swallow the ram whole and spit its decaying bones to the swap unreasonably often.