But that isn't how humans notice exponential change...
We reside in a "level" of order of magnitude in time and space. Things that happen outside of that level, too big or too small, and we simply can't comprehend them. When something crosses from an order of magnitude below our level, to an order of magnitude above our level, that's when we can perceive it.
A block accelerating exponentially from 1e-10 m/s to the speed of light will look completely stationary until it reaches a level of order of magnitude that we can perceive, probably about 1e-5 m/s.
If I tell you I will give you an exponentially increasing amount of money by 1% every day, it matters a lot to you if I start you at 1e-200 dollars because you'll be dead before you earn a single cent. If you lived to 150, you’d be the richest person on the planet. The absolute amount matters because we are physical beings anchored to a particular order of magnitude that we care about.