Narrated ‘Aisha (the mother of believers):
Allah enjoined the prayer when He enjoined it, it was two Rakat only (in every prayer), both when in residence or on journey. Then the prayers offered on journey remained the same, but (the Rakat of) the prayers for non-travelers were increased.
So the gift was small initially and got bigger with time. :)
One reason was: graduality. Muslims were beginners at that time, in Makkah. Allah (SWT) ordered them to pray two raka’at in the beginning and then increased it, so they don’t find it hard to do, keeping in mind the tough conditions in those times.
Travelers still have the relaxation of praying the qasr (short) prayer. And that’s a gift for them.