TLM was not a Wax and Wayne book at all. it was just a cosmere book with wax and Wayne as side characters. the Wax and Wayne books before TLM were about Wax's story. TLM sidelined Wax's story and did a half pass on Wayne's story while focusing on Marasi (not saying I didn't like her storyline, her storyline was phenomenal.) It completed the over all plot, but most of the character arcs were completed in Bands of Mourning. TLM was only necessary because of the loose ends for the plot, and for giving set up for era three. TLM is also the book where we get the most rough separation of the Sanderlanche, splitting it up in ways that felt unnatural for a Mistborn book.
I went a little ranty there, but I really really dislike The Lost Metal. I liked it first read, but then I reread it with the addition of the other books in the series and felt it did not match whatsoever.
If you didn't like Dalinar's or Kaladin's arcs, then that's completely fair. I love OB so much because Dalinar's arc just resonated with me so well, and because I just adore that final sequence.
I highly recommend rereading the book though and seeing if you like it better on the second read, or third, or fourth, or fifth for that matter.