Codeberg is not a commercial product, they've got a mission to provide a forge for active FOSS contributors, not to increase conversion rates. Reducing friction would be nice, that much is good feedback, but their target user is probably picking between them or self-hosting, so fixing half of these isn't urgent. As for the other half:

> OK, so do I register for Codeberg or Forgejo? [...] Do I care it's Forgejo?

If you don't know what Forgejo is or that you can't register for Forgejo, you probably aren't their target user.

> "Software development, but free!" Free is the biggest selling point?

If you don't get which meaning of free is used here, you definitely aren't their target user.

> Why no screenshots of the Codeberg (Forgejo?) UI / wowing me with features? (None on the Forgejo homepage either)

If you've never interacted with an existing Forgejo instance before (including theirs), you probably aren't their target user, again.