There’s also the fact that genres change… or at least the depiction of them in telly and movies changes, and to a lesser extent in books/comics (mainly because their readership is lower than TV viewing figures).
So it is only in recent (ish) years that anyone needed to emulate - for example - Scandi Noir crime series or YA teenage girls fighting dystopian governments. And no-one wanted to emulate the tired old zombie apocalypse genre until 28 Days Later, the Walking Dead, In The Flesh, I Zombie, etc kicked some life back into the tropes.
Or Ye Olde telly science fiction - ropey special effects, terribly choreographed fights. No-one wants to emulate ropey and terrible. Thus instead of emulating that, you put in rules for the physics of cargo loading in 0.37g, and 5 pages of tables of spectral data on stars. Or perhaps that crunch is emulating the scenes from Golden Age SF short stories where the heroes feverishly apply slide rules to solve the plot???
Meanwhile, an observation from one of my best friends. Back in the day, we used to write a lot of fanfic for the SF series we loved all to bits. She’s stopped writing fanfic. Mine has dwindled to a trickle. We discussed this, and she said her reason for stopping is that all the shows she loves these days have no “gaps” to fit the possibilities and world-building and what-ifs of fanfic into. The shows have become too sophisticated. There is little (her words):
chance to explore events and themes that you just know the source material is never going to go near
For instance, I loved the Battlestar Galactica reboot, but never felt an urge to write BSG fanfic. Though I did GM a BSG RPG. I wonder if that was subconscious thinking that any fanfic I wrote about character X would be rendered obsolete if it was later revealed they were a Cylon? (And I was never into writing PWP.) But in an RPG you invent a new ship and a new crew, so the canon characters are tangential to the main RPG plot.
So these days perhaps RPGs can emulate a genre, because there is an expectation that character development and soap opera is part of what you are emulating, not just crash bang action and the physics of hyperdrive?