I do not claim this is the reality of it. I only think sometimes that this could be the case.
Angels, we understand are immense beings; not in a physical sense, but in the sense of complexity, beauty and power. I recall one theologian opining that if we truly perceived an angel, we would not for a second doubt it was God.
So what is the purpose, even the function, of these wonderous beings? Do they “sit” idle? Do they do something in the physical or spiritual universes? St. Thomas Aquinas assures us they’re all of a different genus. None is like any of the others.
Among my mental meanderings, I have sometimes imagined that they greatly resemble what we would call “principles”, or at least are “in charge” of them. One angel, for example, might not only direct the behavior of photons in stars and/or the action of the tiniest of all particles, but “direct” the principles by which they operate, partaking of the wondrous nature of God in doing so. The “thought” of how atoms work is in the Mind of God, the Originator, but the angel “participates” in it and takes joy in its operation as part of the “singing” in the “heavenly choir”; a harmony of such parts and principles working together in a whole so complex our brains would surely explode if an angel so much as told us its “name”; its “name” of course, being its “nature” in full.
Other angels might coordinate with the “atom” angel, cooperating with it to direct the winds of the earth and of Jupiter according to additional principles; those “principles” being the “nature” of the angel itself. And do they have an agency in the chemistry of our brains, our interaction with the environment and our behavior to the extent we do not foil their aciton?
I remember reading how St. Francis of Assisi “saw” an angel in the sky as an enormous being that took up the whole sky. Whatever they are, I think they’re “big” beyond our ability to even come close to comprehension.
So why do they do all of this stuff and most interestingly, why do they bother to interact with such piddling creatures as us? The answer, I think, is that they love God so intensely they love what He loves without even trying to do it. And God has them doing what He has them doing because He loves them and makes them immensely happy being what they are and doing what they’re doing.
Kind of fun to think about.