Journal articles are usually behind a paywall. Preprints are a fully open workaround allowed by most journals.

> Every man and his dog can publish a pre-print and in my opinion it's academically worthless.

Sure but if you look at the authors names and see they have 50 other published papers, you can get a rough idea that it's probably equivalently good to their other work.

Until you've done it yourself, it's hard to grok just how bad the peer review process is. It's like...5% better than nothing.

Honestly you could argue peer review is worse than nothing, as it also filters out actually quality work that violates some dogma of the field.