WARNING: This article includes SPOILERS from Spider-Man: Across the Spider-Verse.The Spider-Man: Across the Spider-Verse screenwriters explain why there is no post-credits scene in the latest installment. Miles Morales' adventures continue as the web-slinger returns to the big screen in this year's Spider-Man: Across the Spider-Verse, with the teenage hero going deeper into the multiverse. For the sequel, the Marvel foe The Spot becomes the central antagonist, with a massive grudge towards Miles, which started in Spider-Man: Into the Spider-Verse.
https://screenrant.com/across-the-spider-verse-cut-post-credits-scene-explained/