If one adds "many" app groups in the app launcher, and/or if the screen size is relatively small, some of the apps aren't reachable anymore. The icons are overlapping each other.
It seems that there is some sort of hardcoded size, because the first 2 rows/groups are always visible. Anything below that gets the overlap effect.
Moreover, the whole screen isn't scrollable, which means that whether or not one suffers from the overlap effect, if their screen size is too small, they can't reach/see some of the icons at all.

See attached screenshots, which are hopefully explicit enough.