It is a mess and those confounding factors do muddy things to a degree. That’s the benefit in a meta analysis, but of course if you put garbage data in, you get garbage data out.
The study you posted is brutal about studies that suggest that salt is not bad for you. It’s a pretty aggressive call out of industry sponsored “scientists” who publish ill-supported findings suggesting salt isn’t bad for people. I deliberately tried to find a less incendiary link, so as not to put you on the defensive. I’m not sure what you’re saying with it, but this now feels more like the Socratic method to me.
I think I am arguing that though people talk as if salt is a settled issue it really isn't
I don't think one can say anything about the safety of salt other than that some is needed, too much is bad.
I feel like salt should be easy since it tastes good until a point, then it tastes terrible, which suggests our bodies know how much we need, but for some reason there are monied interests trying to find proof that all salt is bad, competing with others trying to find how much is safe, how much is needed
That study suggests salt is a settled issue and claims the only financial interests are food companies trying to make salt more acceptable. I don’t think it’s very good evidence for your argument.
Who would financially benefit from the salt recommendations being artificially low?
Well, with an artificially inflated RDA for salt, food companies can use more salt in their products without being labeled “unhealthy.” Salt, as a flavor enhancer and food preservative that stimulates thirst, makes food taste better, last longer, and potentially increases drink sales, all of which are profitable for food manufacturers and sellers. Going further, the medical system benefits from salt levels that are too low or too high, but much more from high levels, as that involves a longer treatment plan.