I think The Silmarillion is fantastic, although I can understand why people expecting a novel would be disappointed or find it hard going. It's more akin to mythical and folk works such as the Eddas, the Iliad, the Kalevala, the Bible etc.

Regarding The Rings of Power, I thought the series are okay so far - there are plot holes and things that don't make sense, but I enjoy seeing how the producers have visualised Middle-Earth. If you get into the mindset that it's a retelling, complete with misinterpretations and inventions, it's quite fun. This is actually more in keeping with The Lord of the Rings (unreliable narrators) and Unfinished Tales (multiple manuscripts). I think Tolkien liked playing the idea of multiple versions, translations and interpretations, reflecting the state of mediaeval literature. In fact, his original goal for his mythos was to create a framework and for others to invent or retell within the framework.

The Lord of the Rings is my favourite book, but after reading The Silmarillion and Unfinished Tales, it's clear that Tolkien bolted it on to his mythos without too much thought into how it would fit in. The same applies to The Hobbit (especially before he rewrote after The Lord of the Rings).

There's a Rohirrim anime that's coming out which adds another interpretation to the mythos. From the trailer, some of the characters look larger than life in typical anime fashion, which is an interesting angle if it takes a "heroic epic" approach like Beowulf or the Epic of Gilgamesh.