So, I've finished the show, and while I appreciate that they're kinda trying to do their own thing, some things don't add upp.
The biggest thing is "Mithril" being explained as containing the light and can heal the corruption by just existing completely rewrites the context surrounding the elves. If Mithril has this trait by default, the elves don't even need the Rings of Power -- and more importantly, the Rings wouldn't even stop working after Sauron's ultimate defeat which is what forces the elves to leave after the fact because they can't sustain themselves and the land.
Further, places like Greenwood who eventually turn into Mirkwood(where Legolas is from) would never change, because Mithril could just keep the decay at bay. Tolkien-wise there simply was no Ringbearer in Greenwood and thus they weren't able to protect the land like say Imladris where Elrond hangs out. And then Greenwood becomes Mirkwood.
I really wanted to discuss the Sauron reveal here but I'm not sure if spoilers are allowed. Long story short, the showrunners have a lot to explain to make this line up with the general lore whatsoever. They've made big bombastic changes and frankly I'm not sure they're able to keep track of everything that now needs to also change or be explained.
- - - Updated - - -
To be fair, Galadriel simply "thinks" that he is dead/lost whatever - when indeed we know that he is not.
I do think it's awful writing. They never even mentioned Celeborn when building Galadriel's character only to namedrop him afterwards as lost/dead. And then of course the whole fandom started shipping Galadriel x Sauron which almost made me physically sick.
I am glad that the actors came out and clarified -- Sauron can't even love in that way and his motivation is ultimate domination no matter what.