There's a lot of same shapes on the piano as well.
And the differing shapes are a bit like how A major and C major have different shapes on the guitar isn't it, for practical reasons you don't use the same shape for those two.
With the clarification that the same shape of the C major chord on the piano, when you move it up through the scale, the same shape produces all the diatonic three note chords of the scale, i.e C, Dm, Em, F, G, A, Bdim, C etc.
And the differing shapes are a bit like how A major and C major have different shapes on the guitar isn't it, for practical reasons you don't use the same shape for those two.