>The problem is with any sort of closed system, the signal immediately gets gamed.

I agree, but..

>Therefore, the open system is the least bad of the available options.

this does not necessarily follow.

>A journal could still achieve prestige by curating and selecting the best available studies and research

See, this is just the kind of thing that I think will just not work when organized top-down like that. "Oh, we'll just make a prestigious journal by only letting the best papers in" - everyone could say that, but what would induce the authors of the best papers to submit them to your specific journal at all in the first place? Currently it's the fact that it's already prestigious, and this reputation has grown over many years through informal social processes that are very hard to codify.

>Scientific publishing is free speech. As such, it shouldn't be under the thumb of institutions or platforms that gatekeep for profit or status or political utility or any of a dozen different incentives that will fatally bias and corrupt the resulting publications.

Of course I agree, just to be clear I am a great proponent of openly accessible science - just think the prestige thing is an interesting corner case.