It's not bad and not good either. I love Tolkien and I'm not as bothered by the departure from the lore as others are (although it must be said that they really do NOT respect the lore in a number of instances), but there are other things that really bother me. There's a number of bad writing decisions, each one in itself not absolutely terrible but they just add up. Some story elements don't make much sense (why would the greatest elven smith not know about alloys?) and some things are contrived (the key to Mordor is a magic sword key that breaks a dam. Contrived enough as it is, but even worse when you ask why Adar and the orcs didn't just break the dam directly). Things like these add up every episode and leave a bad feeling. The most egregious is how elves and humans somehow survived pyroclastic flow from the volcano erupting. This was mind-bogglingly stupid. More stupid than someone trying to swim across an entire ocean. Which is also a thing that happens in this show.
But it's enjoyable and the visuals are largely alright. A good watch if you don't care too much about canon and aren't bothered by mediocre writing.