Why is it that the MCU's Sokovia Accords are still in effect during WandaVision? Captain America: Civil War marked a landmark shift for the MCU, as the various superheroes were split by the introduction of the Sokovia Accords. Following the destruction of Sokovia by Tony Stark's Ultron, and an incident in Lagos where Scarlet Witch accidentally killed a group of charity workers, the United Nations decided they could no longer allow vigilantism to go unchecked. The Sokovia Accords were designed to bring the Avengers and other heroes under governmental jurisdiction, and while some agreed with the move, others believed accountability in the wrong hands was even more dangerous.
But no sooner had the Sokovia Accords been written into law, Thanos descended upon Earth and threatened the entire universe. By his hand, half of all life was wiped out for 5 years, and the Mad Titan was only stopped thanks to the combined efforts of the Avengers and their friends - Sokovia Accords be damned. Watching Avengers: Infinity War and Avengers: Endgame, you'd be forgiven for thinking the Sokovia Accords became obsolete after Thanos. Surely, the Blip proves superheroes are necessary, and that they should be given enough freedom to operate as necessary.
WandaVision proves otherwise, as Agent Jimmy Woo confirms that by stealing Vision's corpse from SWORD, Wanda was in direct contravention of the Sokovia Accords, revealing in no uncertain terms that the law behind the MCU Civil War is still being upheld. One look at what's happening in WandaVision might prove why. At the current time, Scarlet Witch has taken an entire town hostage and is playing fast and loose with the very nature of reality using her Infinity Stone powers. This is precisely the kind of troubling event the Accords were designed to address, and it's arguably the lack of enforcement during and immediately after the Blip that allowed Scarlet Witch to create Westview in the first place. If Wanda was being monitored, as per the Accords, she might've been stopped before the situation became so extreme.
WandaVision also reveals another reason behind the continued existence of the Sokovia Accords - attitudes on superheroes remain starkly divided. As SWORD discuss how to handle the Westview anomaly in episode 5, it becomes clear that Monica Rambeau, Jimmy Woo and Darcy Lewis (the good guys) all give Wanda the benefit of the doubt, empathizing with her grief and entertaining the possibility that she's not intending to harm the residents of Westview. On the other hand, Director Hayward is very obviously a superhero skeptic. He doesn't take much convincing to start treating Wanda like a terrorist, and secretly organizes an ill-advised attempt on her life. Hayward proves that even after the Avengers' heroics against Thanos, figures of authority are still deeply distrustful of those with powers. These split opinions no doubt extend to the general public also.
But there's most likely a broader reason as to why the Sokovia Accords have survived, even though undocumented heroes were responsible for saving the universe not so long ago. As much as Secretary Ross might blame Ultron or Lagos for the Sokovia Accords, the idea of controlling superheroes must be incredibly tempting for the governments of the world - a new arms race where nukes are replaced with supes. This is partly why Steve Rogers was so opposed to the agreement, and the relationship between authority and superheroes will come into focus more with The Falcon & The Winter Soldier, with the U.S. government seemingly creating their own version of Captain America. The UN might've had bigger priorities during the Blip, but the Sokovia Accords are paramount once again in WandaVision.