As far as I understand it, the general scientific consensus is that linguistic relativity does not hold true. More anecdotally, I don't often find myself constructing sentences before having an intuitive (non-linguistic) understanding of what I am trying to express, and the process of putting ideas into words doesn't feel like it would be advantaged by high information density, but rather that the majority of filler-words are useful for smoothing out the process and providing information at a more controlled pace, which can be useful for things like adding emphasis to particular phrases and concepts.