Depends on the orientation of the gain. Most "high gain" antennas are still omnidirectional, they're just focusing the signal out into a horizontal ring, like so:

More dB, and you get a flatter donut with more horizontal reach at the expense of vertical reception. Low-gain antennas reception area starts to approach a sphere, so those don't need to pointed up for best signal as much as higher-gain omnidirectional antennas.
Directional antennas are the ones that need to be pointed at something specific, as they have more of a cone of effect depending on the dB:
