Deeper fantasy books than Mistborn – philosophical in nature / etc.

Hello

I've not finished the last 5-7 books or so I've read and it's a bit frustrating. I read the entire Mistborn series before that, and though I didn't love it, I enjoyed it enough. I'm looking for something a bit more mature maybe or with more philosophical nuance weaved throughout it. I also enjoy reading philosophical fiction – the last great book I read before the slump was The Magic Mountain by Thomas Mann – which is about as far from Mistborn as you can get, but I loved that book..

Some others I liked were the early Witcher books (they got kinda stagnant around book 4 IMO). I don't mind series, but I like stuff that has the pacing and kinda keeps you interested like Mistborn (minus the sieges, yuck) but also makes you think, and I typically prefer high/dark fantasy. I recently tried Earthsea and that was far too dull for me. I used to read strictly sci-fi but I feel I've read… all the good stuff (50s/60s) at least to my taste, and I've been struggling for a long time really to find "my genre". Some others I love are the original Sherlock Holmes, all 2000 pages or so IIRC, early Hornblower – so historical fiction.

I don't care much if it ends up being fantasy – recommend away.

Thanks for any suggestions.