In the physical realm, if one is traveling at speed X in a specific direction, and the direction is immediately changed to a perpendicular direction, instant death occurs even at low velocity. That’s how much a change in direction means. If the new direction were 180 degrees opposite from the original direction, the threshold gets lower.
In the mental realm, we’re constantly changing directions, and the less related a new direction is, the more jarring it feels.
Changing things piece by piece helps a lot, just like it helps a lot to turn the steering wheel just a little bit in a race car. Evening out the change in the direction of the force vectors works IRL and in the mind.
But changing piece by piece can also mean achieving the end goal slower, and can create incongruous experiences while a system is somewhat at odds with itself.
So there’s a choice to make, on a spectrum. Jarring vs smooth, which (sometimes) overlaps with fast vs slow.