Book of Many Things and Keys from the Golden Vault were imo the two best official books of 2023, a year that had what I would consider several serious missteps (Phandelver & Below, Planescape, Vecna).
I think the rollout for Book of Many Things got snakebitten by production delays caused by the deck itself experiencing printing errors and the 2023 release schedule itself having a sub-optimal release pileup late in the year (nothing released from March through July, then 5 books jammed into August-December).