With comics commonly featuring complicated timelines, elaborately crafted story arcs, and more characters than there are actors in the world, adapting them to a film format is always going to require some sacrifices in terms of content and tone. Nowhere is this more apparent than in a character's origin story, which is one of the most common parts of a hero or villain's arc to be rewritten in order for them to fit into the film universe.
Be it that this origin doesn't fit into the universe's current timeline, that it features characters that aren't yet introduced to the series, or just that it's too damn long, time and time again we see comic characters' backgrounds transformed into something almost totally different, with varying levels of success.
On the plus side, this does mean that fans who got into specific franchises due to their film adaptations have a pleasant surprise in store for them, as it means they can read through said origin stories without having heard it all before.
With comic films being even more popular than ever before, it's likely we'll be seeing no shortage of rewritten comic origins for the foreseeable future - for better or for worse.