2 - In the absence of gods, the fey nobility (which are organized and work much differently from anywhere else that I've seen) have increased in power almost to the point of godhood, but without a key spark.
Several worlds that I have toyed with have something similar, with the archfey as the chthonic "pagan gods" whose strife propels the cycles of nature and the seasons.
On the whole when world-building, I typically shy away from the D&D-style pantheons and religions, since I find that D&D (and its like-minded TTRPGs) tends to handle religion, particularly its own, quite poorly. So I enjoy things more like
@prabe's use of fey gods,
@Celebrim's animistic-realism (and an accompanying spirit worlds), along with ethical pseudo-religious philosophies oriented around how one should live in a society in which spirits exist (e.g., a number of Eastern Asian traditions) or archfey have sway over the world.
One idea that I often find myself reusing is the existence of a spirit world in which the spirits often embody concepts, ideas, and the like. Some people view the spirits as simply spirits. Others view them as demons and angels. Others view them as gods worthy of devotion. In one culture, one spirit may be regarded as the God of Justice, but in another culture the same may be regarded a Demon of Vengeance or Wrath. Are the spirits localized or are there spirits that embody larger, more generalized concepts? Is there a god that exists beyond the spirit world, perhaps as the Creator of All? Is the Spirit World itself a Spirit that contains all Spirits? Does the Spirit World represent the Spirit of the World? Or does the spirit world represent the totality of The Divinity? Or is the Spirit World the dreaming of a slumbering god that humans must strive to awaken? Spirits and a spirit world exists, but is there reincarnation? Can one break the cycle of reincarnation? Are ghosts the actual spirits of the deceased or are they false echoes of lives that have imprinted on the spirit world? Is the spirit world the actual afterlife or is there more? Does the divinity of the spirit exist in the human person? If the spirit world exists, what is the responsibility of humankind towards the spirits, gods, angels, demons, etc. of the Other World?
I enjoy the idea of spirits and a spirit world having a concrete existence but humans still forming different religions, theologies, and philosophies around grappling with this spiritual reality. The existence of a Spirit World does not quell theological and metaphysical mystery; it propels further ones.
I was asked to run a fantastical pseudo-Renaissance Venice setting for a Fate game, which I discussed a bit elsewhere. IMHO, the most important organization and cultural influence for the Late Middle Ages or Renaissance was the Roman Catholic Church and the Papacy. So imagining a Late Middle Ages or Renaissance Venice without that is nigh impossible. So with this Spirit World cosmology, I created a Church that regarded the spirits of the Seven Cardinal Virtues (based on Aristotle's four cardinal virtues and Christianity's three theological virtues of faith) as the spirits that best revealed the true nature of the Divine Creator. So there is still a Church, but the ethics and teachings of the Seven Virtues Church will naturally differ from that of the RCC. This gives room to say that homosexuality or sodomy is not a "sin" for characters - a breath of fresh air for modern sensibilities and inclusive tables - but that the Church's issue for all sexuality is Temperance.
It was a short campaign, so I did not get to explore the intricacies of piety, though one character's sister was a priestess of the Church of Virtues who was attempting a magical ritual to seal a tear into the spirit world. However, one could easily take this Pseudo-Renaissance Church of Virtues and imagine other faiths and heresies. There might be a heretical sect of the Church that believes that there are only Three Virtues worth following. Or these heretical splinter sects may reject all spirits as relics of a "paganistic polytheism" that interferes with venerating the Creator. What about a competing religion that teaches that there is only one spirit worth following: e.g., the Spirit of Truth? Or a religion that believes that all spirits are a manifestation of an ever-changing Divine Will?
I have gotten far more mileage out of this basic conceit for a world than nearly any other because the various cultures for any and every new world that I create may have supplied their own prevailing set of answers or questions about this Spirit World. Gods, demons, devils, spirits, angels, and fey can be interchangeable without me sweating the details. I can say that religious tradition/cultus A believes X about the Spirit World and the spirits, but that religious tradition/cultus B believes Y about the Spirit World and these spirits, without needing to supply a definitive answer.