As one of the Kang variants introduced in 's mid-credits scene, Marvel Studios can explore Fantastic Four's history with the villain before Avengers: The Kang Dynasty.

Source: https://screenrant.com/avengers-5-kang-dynasty-fantastic-four-missing-problem/

In Spider-Man: No Way Home’s mid-credits scene, just as Eddie Brock decided to seek out Spidey, he was transported back to his own universe.

Source: https://www.cinemablend.com/superheroes/spider-man/turns-out-venom-let-there-be-carnage-nearly-included-more-of-tom-hollands-spider-man

In the mid-credits scene, Monica wakes up in a medical lab with her late mother, Maria (Lashana Lynch) by her side.

Source: https://comicbookmovie.com/captain-marvel/the-marvels/the-marvels-director-nia-dacosta-says-she-was-pushing-for-more-spoilers-in-the-movie-a208043

In the mid-credits sequence of Guardians of the Galaxy Vol. 3, we see that there is now a new group of six that has picked up where the preceding team left off.

Source: https://collider.com/guardians-of-the-galaxy-new-team/

Often, these mid-credits and post-credits scenes included with Marvel movies tease the characters and conflicts of the movie franchise's future.

Source: https://gamerant.com/movies-that-did-post-credit-scenes-before-marvel/

Teenage Mutant Ninja Turtles: Mutant Mayhem teased the rise of Shredder in the mid-credits scene, and the villain’s introduction helps avoid past franchise mistakes.

Source: https://screenrant.com/tmnt-mutant-mayhem-shredder-avoid-franchise-mistakes/

The mid-credits scene in reveals Shazam being recruited for the Justice Society by ARGUS agents John Economos (Steve Agee) and Emilia Harcourt (Jennifer Holland).

Source: https://screenrant.com/shazam-2-casting-criticism-james-gunn-response/

What’s more, Shredder’s appearance in the mid-credits scene shows that the filmmakers understand how crucial a character he is, as well as the fan anticipation surrounding his arrival.

Source: https://screenrant.com/tmnt-mutant-mayhem-shredder-avoid-franchise-mistakes/