World Builders: What Would Marvel Do?

If you are a creator of fantasy universes and worlds, you might be familiar with the euphoric rush of the initial brainstorm.

After several years of gestation, a new universe is ready to be born and there are so many amazing things you want to incorporate into it, that during the initial brainstorming a wave of creativity pours out of your very being.

You decide you want a cyberpunk world, but with an eldritch horror tone, but also there are powerful alien forces trying to infiltrate earth (but it's not earth, it's a clone of earth where the continents are all different).

There are sea tribes, merpeople and psionics, and there's also time travel back to previous generations of this world where arcane martial arts were taught by the ancient ones, in order to prepare for the titanic battle with the Darkseid/Sauron/Thanos type dude who is invetivably coming to cause some trouble.

After you've written it all out and the initial wave of euphoria has passed, there's a slight come-down because you start to see two things.

Firstly, the thing you want to build is huge and it will take several years and hundreds of hours of work.

Secondly, you've got too many working parts in your world, two many different competing concepts, but you don't know which ones to keep and which ones to dump. It breaks your heart to 'kill your babies' and conventional writing suggests that you should simply be brutal and swing the axe.

If you do that though, you wind up with a truncated world that is accessible to your audience but won't necessarily wow them or excite them. If you chopped up all the concepts listed above, you'd create half a dozen worldbuilding experiences that your audience is already very familiar with.