tbc im not against sequels as a whole, im against the sort of endless brand farming and re-farming that is dominating American cinema and has been suffocating creativity at that level right now.
I also somewhat disagree that sequels are an inevitability of big budget cinema. Two of the most successful films last year weren't sequels and cinema for the longest time thrived without anywhere near the proliferation we see today cause consumers weren't obsessed with them.
I honestly suspect the pendulum swinging back a bit and I think we are seeing that.
There will almost certainly always be a place for sequels and certain brands, what I think is happening is that endlessly farming nostalgia and familar brands is no longer the superior guaranteer it once was as consumers are showing a preference shift and running into the double edged sword of nostalgia farming where fandoms are never satisfied
Honestly, considering humanity has basically been retelling familiar stories on a regular basis for long, long before cinema, I don't feel the same way as you. And honestly, I don't see this as any different when we've had genre domination since the beginning of cinema with westerns. Even the 70s, 80s and 90s period of cinema people was poetically about is somewhat exaggerated in terms of experimentalness and originality when you actually look at the top 10s for each year.
It's just the medium back in the day was less in terms of tech and expectations. And more films were able to be sustained soley by enthuist audiences, similar to how the wild west of gaming was low tech and also easier to support by enthuists and smaller audiences.
I also don't think you're quite seeing a preference shift from non-enthusists you think is happening. Considering how many original IPs even here just flat out get ignored. There are definitely breakout hits, but it's not the pendulum swing you're describing. Heck, to be blunt? The fickleness you're describing with fandom happens with new and experimental films too. If fans of other genres acted like horror fans did and supported new ips on the levels they did, we would see way more sci-fi, dramas, ect. But people are absolutely just a fickle about new things despite asking for it. The fandoms are absolutely fickle, but at least enough of them still tune in even when they vocally are frustrated (or maybe the ones who are vocal aren't as large as they think).
I know there's a lot of yearning for various entertainment industries to be a certain way, and for audiences to go towards those things in droves regularly. But I also think there needs to be an understanding that depending on your level of personal investment in the medium, you're not going to be as bothered by similarities in things. Enthusiasts are always going to want to see something reach it's full potential, but not everyone is going to reach that level. Not to mention people like both making their own spin on things, and seeing new takes on the familiar. It's how Greek myths, monster stories like Dracula, adventure stories like Robin Hood, ect keep surviving.