In a smaller pot that has trouble retaining moisture yes. In larger beds such as yours toomuch moisture leads to root rot and fungal issues. It will contain air and help oxygenation, but that same ability can be a double edged sword. If you are in a dry climate it may be helpful. Here in the humid south its more that we have plants staying too wet. So it depends as usual on what those plants want for their soil. A vast majority like good drainage. Pure perlite is used in dutch bucket hydroponics. Its sort of like lava rock. Those systems get turned on and off on a cycle, the perlite retaining moisture in between. It gets mixed in a little into potting soil with some water retention beads because heavy evaporation and drainholes dry a potted plant in a few days. I think it is designed for a weekly watering plan. Raised bed soil can be heavy if they are deep at all. The structure therefore can compress, smothering or drowning roots. The bigger the beds get, the less a lightweight and puffy highly composted mix becomes useful to the extent that watering and weathering cause settling and compaction around roots. Raised beds need some planning because they are a design system not a natural system, and variables such as size and depth and seasonal solar energy are all "chooseables" so there is not a real rigid set of rules that I can discern.