What's the point of 3NPS?
On guitar, the way notes are distributed across multiple strings makes all the difference in terms of technical facility.
When we play scale patterns using the '3-notes-per-string' method, aka '3NPS', we can play fluidly more easily than when using any other fingerings or patterns.
Whether we use alternate picking, sweep picking or legato picking, and even tapping, each of these techniques works magnificently with the 3NPS method.
Here's an example from the C major scale.
It is 3NPS pattern number 3 from the scale.
Notice how the fingering shapes are exactly the same on each of the bottom 3 strings.
Notice how the fingering shapes are the same (only shifted 1 fret) on the G and B strings.