So you wanted something new, while playing replaying the same dungeons and raids that are known eye closed … well tons of logic in that.
When you say you want something NEW, you based that with what, comparing WoW with what ?
Vanilla, TBC, Wotlk, Cataclysm had nothing new.
MoP - challange dungeons timed, scenarios
WoD - had garrisons … , and was somehow alt friendly due to fast leveling and fast pvp gearing in ashran
Legion - was best in adding new features M+, Mage Tower, Suramar, somehow a world pvp tryout (better then nonthing), legion class hall with great class stories, invasions, beatutiful zones
BFA - beautiful zones, island expeditions, visions
SL - a good start to ALT friendly with the addition of Threads of fate, but actually a bad course to ALT friendliness; torghast
DF - MOST IMPORTANT: SOLO SHUFFLE, ALT friendliness, pvp gearing without the useless honor grind for pvp, the insane multiple ability to gearup near highend, beside the known ones (raid, M+, unrated pvp and rated pvp) now we got world pvp activities and currency, world pve activities and currency, beautiful zones, great ministories, dragon flying.
Dunno what you expect, but DF is not legion, feature wise, but hell, we seen Legion after 6 expansions :). DF it is really appreciated because of choosing the non-chooring and ALT-friendly path, leaving the player to actually play the mode it wants to play and not being forced to do cross paths (pve pvp etc.), all that while offering a good gearing variety and resolving issues with pvp gearing, and ofc pvp solo shuffle resolving the awfull LFG 30mins problem.
Overall, for raiders, I think all expansions were great, doing new dungeons and raids with guild and friends.