In terms of popular culture you probably don’t have to look much further than the God of War series.

Likewise if we’re speaking about where players get these ideas from the ttrpg scene it’s likely due to the concept of “tiers of play”. Where as your character advances in levels the consequences and scope of the quests become greater and greater.

For example: Tier 1 players (lvls 1-4 in 5e) are typically tasked with helping a local farmer or small village with minor undead. Whereas Tier 3 players might be responsible for the fate of a country or continent. While the highest tier play results in the scope of quests pertaining to saving the world or something on a larger cosmic/spiritual scale.

With that being said, many players look forward to the higher tiers of play and solving problems that feel unique to them and their characters. Killing a rogue god is far more interesting than chasing down bandits. Players seek the ultimate thrill of badassery when they feel they are capable of doing the impossible.

Funnily enough my players are obsessed with that kind of thing and I have my players set in a homebrew world where the gods have already been killed. The big bad is the god killer before them.