Warning! Spoilers for Venom #200 by Marvel Comics below.
After the events of King in Black, Spider-Man blamed himself for the God of Symbiotes' arrival in the Marvel Universe, as he believed bringing the Venom symbiote to Earth was ultimately what caused the later attack. However, Venom just revealed to Peter Parker that Knull's army didn't find Earth because of him and he shouldn't shoulder any of the blame for what happened. Peter's biggest mistake wasn't his fault.
Spider-Man thought he brought the first symbiote to Earth when he kept his alien suit after the events of Secret Wars. Famously, the symbiote began corrupting Peter, which led to him splitting from it. However, when Spider-Man lost the suit, it found a new host in Eddie Brock, leading to the creation of Venom. In the King in Black event, Knull came to Earth searching for Eddie. Because of this, Peter felt responsible for the death and destruction the God of Symbiotes caused, as he blamed himself for the domino effect that led to the dark god invading his home planet.
In Venom #200 by Donny Cates, Ryan Stegman, JP Mayer, Frank Martin, Eddie calls a much-needed meeting with Spider-Man, as the former Venom has become the new King in Black and is using his powers for good instead of evil. Spider-Man tells Eddie he owes him, as he stepped up when he couldn't. Eddie immediately squashes the notion that Peter is responsible for the King in Black's attack, revealing symbiotes have been on Earth for thousands of years, including ones fighting in Vietnam, being part of the Weapon Plus program, and inspiring The Legend of Beowulf.
Peter is shocked at the revelation and asks Eddie how long he knew. Brock tells him he found out the day a symbiote dragon showed up on Earth. He admits he should have told Spider-Man about the history of the symbiotes, but the two ultimately bury the hatched. Peter still is confused to see Eddie become a God-like figure but agrees to help him if he ever needs it.
Spider-Man really beat himself up over the symbiote invasion, as he believed he was directly responsible for Knull finding his home and trying to destroy everything and everyone he's ever loved. Now, he can take a mammoth weight off his shoulders knowing he didn't bring the first symbiote to Earth. Spider-Man's biggest mistake actually wasn't his fault at all. For a hero who cares deeply about responsibility, he will surely sleep better knowing the King in Black's attack isn't all on him. Venom #200 is in stores now.