There are many reasons why the public and scholars can’t seem to stop talking and thinking about the mythologies of the past. Part of the reason is that, of course, human creativity often builds on what came before.
As a result, plenty of modern characters were either inspired in mythological figures or are outright part of ancient mythologies. Asgard’s inclusion in the Marvel Cinematic Universe is probably the most famous recent example. The movie reimagining of Asgard has little to do with the real thing, but its existence in a piece of mass-media entertainment does get people interested in the origin of words like Mjölnir and Yggdrasil.
Aside from mere exposure, there is also a practical reason why we should study the legends of the past. Mythologies often offer us a glimpse into how the ancients thought and saw the world. Many legends and deities lived for centuries as part of oral traditions before being finally put to writing, which means that some of the mythological legends we know today are so old that we can only guess at their age.
If you are a deterministic person, you can say that the present exists as a natural consequence of the past. This means that we can piece together our reality by understanding what came before, and how the civilizations that came before ours saw the world.
Even if you don’t believe any of that to be the case, there is still something in us humans that makes many of us deeply curious about the thoughts and lives of our distant ancestors.
Finally, one of the biggest reasons why mythology is still discussed is because it is still changing. New discoveries shine light on old stories, changing our understanding of how the ancients engaged with their own religious beliefs. This keeps the field fresh and interesting for scholars old and new.
If you want an example of how fascinating mythology can be, just read this article on Hermes Greek god. You’ll see how deep the discussion around a single god can be.