The reason the waves do not cancel each other out at every position is that to do that the waves from the two sources must be exactly out of phase at every position and that is impossible.
Suppose that you have two sources $A$ and $B$ emitting waves of exactly the same frequency and wavelength at each other.
Further suppose that the waves are emitted from the sources are exactly in phase with one another and the sources are exactly one wavelength, $\lambda$, apart and ignore any loss of amplitude as the waves get further from the sources.
Position $C$ represents a path difference of $BC - AC = \frac \lambda 2$ between the two sources.
This means that the waves from source $B$ are $\pi, 180^\circ$ out of phase with the waves from source $A$.
So whatever the displacement of the medium due to the wave from $B$ the wave from $A$ produces a displacement of the same magnitude but opposite direction at position $C$.
So the net displacement is zero all the time.
There is certainly a cancellation of the two waves at this position and the same is true at position $E$.
These positions are called nodes.
However there are no other positions between the two sources where the waves from each source arrive $\pi$ out of phase and so there cannot be complete cancellation at any other point.
For example at position $D$ the waves from the two sources arrive exactly in phase with each other and you get twice the displacement of the medium than that due to the wave from one source.
Obviously you can increase the separation between the sources and get more nodes but in between the nodes complete cancellation is impossible.
So the standing wave pattern is so called because of the presents of positions where there is no movement of the medium (nodes) there being no net transfer of momentum or energy but there is energy associated with the standing wave itself.
I do not know if you have yet studied two source interference but in some ways the interference pattern has a resemblance to a standing wave pattern and is a standing wave pattern on a line joining the two sources.