Why do we think that Inflation and Dark Energy are separate independent phenomena?

It seems like they could be related, as they both involve space itself expanding, but I've never come across anything suggesting that, so I'm sure there's a good reason that I'm just not aware of.

My intuition would be that the universe would start with some absolute total "inflation energy" causing space to expand rapidly. As the universe gets bigger, it would get diluted as its stretched across its larger and larger amount of space, which at some point would cause it to slow down. After a while though, it would hit some "floor", which would be much lower than in the beginning, but still above zero, which it wouldn't be able to go beneath. Once it hits this floor, the much slower expansion would appear similar to how we see dark energy.