GoT died because the writer was replaced by a pair of hacks when the writer couldn't write fast enough to keep up.
This is a great theory!
I think the creators of HBO's GOT ended the series because they were rushing to work on:
]] Benioff and Weiss inked a five-year, $250 million partnership with Netflix in August to make film and TV projects exclusively for the streaming service. The move was head-scratching at the time, considering the pair had already committed to producing Star Wars movies for Disney—an undertaking that was likely to take many years and leave little room for anything else.
https://qz.com/1737729/gots-benioff-and-weiss-picked-netflix...
I dunno, now that Endgame completed the movie storyline that had been building for a decade, and their spearhead TV show Agents of SHIELD is over, I've almost completely lost all interest in the MCU. I've seen similar sentiments pretty regularly elsewhere, and wouldn't be surprised if its prominence also fades despite continued releases.
Past obsessives moved to other newer things after a few days.
It's an incredibly curious thing and the opposite from the never ending marvel material that gets released.