> I'm honestly confused why researchers in one or a few fields haven't already gotten together and said e.g. "okay, instead of considering publishing in 'Cell' to be the most prestigious for biology, let start an open-source co-op journal called 'Flagella' that by design has exactly the same level of publication pickiness, and works with exactly the same peer-reviewers, as 'Cell'; and then let's all walk around getting signatures on these threshold trigger agreements at our field's conventions, where those agreements would say that that once we have enough people behind this, we'll all switch over to publishing in 'Flagella' at once, considering it to be just as prestigious as 'Cell'; and after that point, we will all be contractually bound to never publish in 'Cell' again."
There are several reasons why this has not happened.
1. The most important, researchers are not publishers and are already completely overloaded with other work (most academics typically work 60h+ a week). They neither have the time not expertise to get this started and make no mistake there would be a significant effort required to get this started.
2. There is a certain percentage of researchers who are quite happy with the status quo. These are typically the very successful researchers which don't lack funding so don't see a problem with this (obviously there are exceptions) . Unfortunately they are often also the ones who have a disproportionate influence so if they are not on board the effort is much harder.
3. The vast majority of researchers highly depends on publications in high impact journals for their grants, careers, jobs... (for younger researchers a publication in e.g. Nature can really set off your career). For a new journal to get a high impact takes at least several years, so this is a bit of a chicken and egg problem. Before the journal has the high impact most can't afford to send their best work there, but without that work you don't get the impact.