Shadowlands utilized the same set of rules of world quests in the endgame, reputation grinds, and Mythic+ progression that the game's highly-rated Legion and, later, unpopular Battle for WoTLK Gold Azeroth expansions did. Although those systems worked well in Legion, where it was original and new, all but Mythic+ had worn out their welcome in Battle for Azeroth. When those systems then came forward in Shadowlands to be used for the second time, they felt like Blizzard was running out of fresh ideas. When it came to Shadowlands, WoW felt less like a game that was to be played and more like a list to be completed on a daily or weekly schedule.
This was not helped by the fact that content updates were extremely rare. The majority of expansions that WoW has had include at minimum three major content patches. Shadowlands On the other hand, received two and its most recent and final patch for content being released just only recently. Two major patches puts Shadowlands within the same group as the 2014's Warlords of Draenor expansion, which was another low point in the history of the game. The fact there is a requirement that WoW is still requiring a monthly subscription to play it makes the seven-month waiting periods between Shadowlands new content patches worse. The pandemic certainly had some impact on production and workflow, however that doesn't make the lack of new activities to play in the game an easy pill to swallow for players. Since the recent Eternity's Finale update marking the conclusion of content updates for Shadowlands and a brand new expansion that's not even released, it's likely be another long wait until new content gets to the games.
The Jailer is known for being one of the least unsatisfying character in World of Warcraft history.
None of the above refers to the story behind Shadowlands that has been another big issue for longtime fans. In Shadowlands, Blizzard introduced a new villain, the Jailer. He was the ultimate mastermind behind not only major events in the past expansions, but also lore-forming events that date back to World of Warcraft. The Jailer was supposed to be a brilliant schemer who had been hatching his plan to alter the rules of reality for years. In reality, his plans made little to no sense and he had any more to say beyond the stereotypical "prepare to die, mortals" style. The villain was slammed by fans, laughingly calling him playing a game of 4D Chess that nobody even Blizzard had a clue about. The Jailer was revealed at the conclusion on the final Shadowlands attack the Jailer proved to be a mere persona and more of a plot device, serving only to reveal a previously unknown aspect of threat to buy WoTLK Gold the universe that was never before seen. Through this, Blizzard discounted decades of lore and character development for the iconic characters of the franchise like Sylvanas and Arthas which all in the service of a throwaway villain who added almost nothing of substance to the universe of the game other of the apparent power to make everything he interacted with become worse.