The universe is expanding exponentially to an exponential power.
The universe HAS TO expand like that, otherwise it would not exist.
It really doesn't have a choice. If the acceleration were slowing, it would mean the universe is reaching a certain "point" or value - even asymptotically; and any point is arbitrary making existence "unsupportable." Arbitrary cannot exist on its own. There is no reason an arbitrary value should exist while another does not.
Even the universe expanding at a specific rate is arbitrary. It has to be accelerating at an un-pinnable/undefinable rate. Anything that could be defined, or defines the universe as arbitrary would cause it to cease existing.
This is applies to both space and time.
Time is accelerating exponentially to an exponential power.