People are complaining that this series is bad, because it is not true to the lore. However I have read most of the books, several times. There are a few minor inconsistencies, but so far the first two episodes are consistent with the lore. Galadriel was the primary foe of Sauron, during the second era, and Tolkien did not write much more then notes about this time period.
People are stating that her brother is not dead during this time period. That is a technicality, Finrod, fought in the Dagor Bragollach, the battle scene depicted early in the show. Without going into spoiler territory the events of that battle, lead to the events of Finrods death, at the hands of Sauron. If you doubt me try reading The Silmarillion, it is kind of a major plot point. The fact is that Sauron killed Finrod is consistent with the lore, but elves reincarnate, and because of this he is alive.
There are many drafts of the lore for the second era, and for most it is not clear which version Tolkien ultimately decided were cannon. However on the decided cannon by J. R. R. Tolkien, and later his son Christopher this show is mostly consistent.
There is some room for creative interpretation, and ultimately J. R. R. Tolkien wanted to create a new legendarium. Legends grow and change over time, and while Tolkien did not like allegory, he does admit that The Lord of the Rings, is one. It is about good triumphing over evil, about how pride corrupts, about how unity and understanding of different peoples will lead to victory. How it is important to be forgiving and humble, and the dangers of blind hatred. I think that so far these themes are conveyed in the show. It is obvious that those who oppose these themes dislike this show because it is leaning into these central themes. There are flaws, and often you will hear about orc genocide, but Tolkien himself was later conflicted about the nature of orcs. Ultimately they are beings who have been corrupted by hatred, and it is for Eru Ilúvatar, or the god of The Lord of the Rings, to redeem them. The orcs are a force of evil whose opposition leads to greater good. In most cases this greater good is an understanding and love between the different peoples. So many complain that this show is "woke", but there is a reason Tolkien is loved among hippies and those who some consider "woke". Tolkien was Catholic, and he did include many aspects of Christian values in his works. The most prevalent being love and hope. It is obvious that he believed that the forces of good use love, hope, and unity, while the forces of evil use hatred, division and lies. A common theme is that the proud are corrupted by a deceitful lord of darkness into committing great evil while intending good. They eventually realize this evil, and some repent, while others who have grown too fond of power will continue in their evil ways. Those who continue to commit evil, are eventually destroyed, often by the very corrupt fruit they have planted. I think that Tolkien may not have approved of all of the story telling methods used in this show, but given his belief in love and hope, and in redemption he would not condemn the entire work as too " woke".