Generally yes, photography makes you more observant, but in some cases I think it can go both ways. In one video, noted macro photographer Thomas Shahan walks along a forest path as someone is conducting an interview of him, and he remarks that he's never noticed a particular cave before because he's always looking down to try to spot jumping spiders as he walks by.
But as I train my powers of observation to discover small insects, what shooting macro has
definitely given me is a much better appreciation for the amazing diversity of life that's in our very backyards. For example, I never would have thought that within 3 meters of my backdoor, I could pretty easily observe at least four different species of (minuscule!) jumping spiders, some of them living on/in the very walls of my house! I never suspected that there are so many species of dragonflies and damselflies, or even types of bees. I've now seen and photographed species of flies that I had no idea existed. It's still amazing to me to stop and observe a patch of blooming flowers for a few minutes and to just discover there a richness of life that I had never seen, even though I had casually walked those grounds (or similar ones) countless times before I started shooting macro.