Concerning other comments on funding, I wanted to add that some journals don't need much money (hosting is basically free, workload shared well by editorial board). On the other hand funding can and does come from universities and their libraries (money not spend on subscriptions), research institutions, museums, and donations (sometimes seen as volountary APCs by those who have the money from grants).
Also, it's absolutely worth noting, like you point out, that different fields have different processes for accomplishing the same thing. It seems that younger academic fields are a bit more independent of the traditional structures. I hear that in Computer Science, conferences carry more importance than they do in some other fields, for example.
In other fields, there's a lot of inertia to deal with.
It's also important to keep in mind that "Think, Check, Submit" is an initiative backed by traditional publishers (of the "gold open access" kind), and I think they are making this a bigger problem than it actually is. In my area, everyone knows which conferences/journals are reputable, and everyone knows that all others are essentially scams (especially if they have APCs). I have never seen anyone make the mistake of publishing valuable material with a scam publisher.