You can't kill off your heroes, not when the actors are the ones getting people in seats. Even if it makes sense, audiences know that your characters aren't staying down. Half of the time, characters returns are announced before the film featuring their death is released. Look at Endgame. We almost got a Far From Home first look before an Endgame trailer.
That said, it's not just Marvel characters that seem to have filled their Hells so full the dead must rise. Star Wars, Sony, even some Stephen King films will definitely be visiting the grave, a shovel and difribrilator in hand. It's one of the best ways you can extend drama - never have your characters die!
It's like Game of Thrones in reverse - Valar Livelongus. There are some characters who are so interesting and so very juicy that regardless of logic, they have to come back in the sequel.
Here are some characters who just won't stay in the ground.
9. Luke Skywalker
Luke Skywalker is the first Jedi any of us ever met. He is the true key to the Star Wars Universe. Everything else has been about him - the prequels are about how he came to be and the sequels are about his legacy. Because of that, and the fact that he died as one of the most powerful Jedis ever, there is no doubt that he'll be back for the next film. Luke's Force Ghost has already been confirmed for Episode 9.
But don't expect that to be the end. As a Force ghost, he'll be able to return for any Star Wars film in the future - and if certain rumors are true, we might even get a new series starring a young Luke Skywalker. Regardless of rumors, there's also solo films still in development and Luke Skywalker was out in the galaxy for a loooooong time. You know that Mark Hamill will be down to take up the lightsaber again. Especially for a cartoon showcasing Luke's coolest solo adventures?
Expect Luke Skywalker to continue returning for as long as Mark Hamill is alive, and then for a couple of movies after that, too.