The show is set an indefinite length of time after Morgoth's defeat, because the show has played fast-and-loose with Tolkien's timeline, meaning you can't really assert anything categorical about it. Sauron starts building Barad-Dur in SA 1000; the rings are forged in 1500-1600; Elendil is born in 3119 etc. etc. etc.
One of the more frustrating things about exchanges with apologists for this show, is they'll latch on to one or two things which are both consistent with their position and lore-friendly, while ignoring vast tracts of lore-defying choices which the show has made. These few consistencies are then framed as especially significant in their faithfulness, illustrative of some deeper (and still, as yet, rather vague) "truths." Cherry-picking, while wearing 270-degree blinders.
I return again to the Sauron-Galadriel encounter contrivance, and its subsequent unfolding, because it strikes me as one of the most offensive in terms of the deeper themes in Tolkien's world.
Setting aside the implausibility of attempting to swim across an ocean, and the improbability of being rescued (twice by Sauron; once by Elendil), how in any way does this correspond to notions of providence as envisioned by Tolkien? Where providential intercessions occur, they are implicitly the action of Eru upon the world - Gandalf meeting Thorin in Bree; Bilbo finding the ring; Bombadil's intervention. How is a chance meeting with Sauron faithful to this deeper theme?
Sauron is afloat on a wrecked ship bobbing around on Belegaer. How did he get there? As a servant of the Great Enemy, what business does he have being here? - the oceans and rivers are Ulmo's domain; Melkor and his flunkies are terrified of them. The Enemy is powerless here, and fearful, because the Music of the Ainur runs clearest still within the waters of the World. How is Sauron's presence here faithful to the deeper themes?
The answers to these questions are fairly clear to me - bad writing setting up false drama; ignorance or dismissal of a wealth of ready-made, potent symbols and connections, in service of a mediocre, anodyne cinematic experience.