The guitar and keyboard can both of course play the same chords, so how do they differ in terms suiting a particular genre
Well basically if you start at a beginner or intermediate level there are limited chords you would normally play of the guitar. These would be most the major chords such as Gmaj, Dmaj and Emaj or Fmaj, definately chords that you won’t normally use in Neo Soul. Playing minors and extended chords which are more used in Neo soul is more of an advanced step for most people on the guitar.
On the other hand, on the keyboard or piano, even beginner players can find extended or minor chords just by simply counting up the scale. There is no need to actually remember the fingering pattern like on the guitar. Take the C scale for example. The Cmaj is a triad counting 1,3,5. The Cmin is simply shifting the 3rd key down 1/2 a step. The Cmaj 7th is simply counting 1,3,5,7 on the white keys. The 9th is 1,3,5,7,9 and so on.
This is why it maybe a lot easier to improvise and play around with chords on the keyboard.
However an experienced guitarist with full knowledge of all chords shouldn’t have too much problem, but it takes a good guitarist to be able to do that.