I noticed that there are a lot of attacks on the show on social media (particularly on youtube, this has been going on for a year), because it was made by Amazon, is based on appendices/Silmarillion and it has woke casting.
There isn't much about pre-LOTR Galadriel in Tolkein's Silmarillion. It's basically a fantasy-history/lore book, and rather choppy/disjointed at that. She was a sort of demi-goddess. I don't recall anything about her wearing Aragorn's outfit and being an adventurer lol. She was more of a political leader.
I haven't had a chance to watch the episodes yet but it looks like they got the Golden age/decline of the elves rather right. In Tolkein's universe, in the prehistory Elves were superhuman/higher beings that lived well. But they declined, in part due to the wars. By the time of the Hobbit/LOTR the elves are already very declined, and Galadriel is passive and leaving middle earth.