There is a common misconception concerning perlite: that it aids in providing moisture to roots. This IS NOT true.
And usually the reason for this confusion is because perlite and vermiculite are often confused.
The primary usefulness of perlite is to improve drainage. The concept of drainage is moving moisture through the soil and therefore away from the roots - i.e., less moisture.
There are moisture control potting mixes available on the market. First of all, the name, "moisture control," is meaningless when considered literally - that is, one might want moisture controlled to a minimum for cacti, or one might want it controlled in to any unlimited array of degrees of moisture. The most familiar moisture control mix is designed for more moisture retention - in order to make more moisture available to the roots. Well designed mixes of this sort do not contain perlite because adding perlite defeats that purpose.
As a beginning gardener, one must become aware that plants have environments with climate conditions to which they are adapted. The easiest example is cacti. Cacti are adapted to desert conditions. A boggy environment would spell quick death to cacti - they are not capable of that extreme degree of adaptation.
Some potting mixes exist to allow the gardener to accommodate/compensate for the specialized needs of plants being grown in the gardener's "alien" environment (one that isn't natural to the plants). Specialty potting soils exist for orchids and cacti, etc.
The home gardeners primarily focused on rooting new plants are rare. Folks focused on this are generally in the nursery industry. So, the value of perlite for a rooting medium is irrelevant to the discussion of perlite's qualities in a potting mix or when added to one's garden soil (by coming along to the soil when a plant potted in a mix with perlite is planted directly into the garden).
So the point here is that if we don't mix up the ideas - a good medium to root in vs. a good medium to grow in, and we understand that roses don't want to drown, but that in general they do like water, then we realize that perlite is not user friendly in this regard. And it can be considered dangerous in soil like sand, where drainage is the primary quality.