There are a bunch of field-specific preprint services like arXiv: PsyArXiv, SocARXIV, engrXiV, AgriXiv, etc. The OSF also hosts preprints for various disciplines.
The important thing to remember is that preprints are not peer-reviewed and have not been vetted in any way. A paper may change a lot (or just a little) between preprint submission and final publication. A recent paper of mine had a few sections added for clarity, which wouldn't appear in a preprint.
Some have, but even that depends on licensing options. Many universities have institutional repositories with folks working hard to get affiliate papers uploaded for open access, but they still have to follow the publisher's license. Some publishers allow OA upload in an IR after an embargo period. Some do only if you pay for general OA publication (extra cost on top of the regular publishing costs, although subscribe to open or read & publish deals sometimes take care of the fees). Some allow it as a matter of course. Some allow it if the author requests it at some point. Some just don't care and never allow it.
There are also university presses or nonprofit publishers, but their models often aren't that different. It should be treated as a public service, especially for research given public monies to be completed, but it's currently just business as usual.
I felt this way as well. That top tier of subscription maxes you out, and they give no incentives. I assumed it was because they shrugged and thought, "They can't level up, so we have them where we want them. Let's upsell the others instead!"
It doesn't really do anything other than (potentially) verify someone or an organization really is who they say they are. It probably matters most for well-known folks or orgs that you need to know are real. One example is how confused people are about Mark Hamill, who did move over to Bsky, because there are so many impersonators.
Another example is the US Consumer Product Safety Commission. I can verify they are who they say (and trust their posts, hilarious or not) because they've used their gov site to verify their account.
They'll have non-member options for sellers once it's out of beta, too. Supporter members can also sell (lower buy-in cost), but the Coop commission is higher (not as high as non-member will be).
I've purchased several things there, and I've loved everything. (I'm not an artisan or crafter, just a buyer of art and craft.)
Processional: "She's the One" by World Party for groom and family, "Book of Love" by Peter Gabriel for bride. It ended up being perfectly timed, because I was able to sing the last verse to my favorite person when I got to him (which is about wanting to give each other wedding rings)
With Pebble shutting down already, I'm going to stick with Beehaw where it ends up. The ethos around discussion and understanding is the reason I have this account.
They've added some functionality for findability that might be more useful now!