Partly true. You can only go so far with keywords at a specific time. However, the approach isn't totally unscalable, as you can work your way up to targeting

Partly true. You can only go so far with keywords at a specific time. However, the approach isn't totally unscalable, as you can work your way up to targeting more and more trafficked keywords as your app grows. An exptremely important part of ASO is to keep on doing it every time you update your app.