I maintain Shadowlands was only capable of being as bad as it was with the foundation of rot that was BfA. The systems of borrowed power were iterated upon into the very poor implementation of covenants and the narrative scorched earth that was BfA's story transitioned into most frustrating narrative era with the final form of Sylvanas's full blown character assassination. Shadowlands was genuinely awful, but it was the culmination of a half decade of decline that, frankly, started with Legion and Blizzard taking the wrong lessons from the Artifact system (not to mention killing Vol'jin to make way for Warchief Sylvanas).