I checked with the relevant team. Here are some conditons that can cause the publish-to-web functionality (now called "View-only link", btw) to not show up:
- You have a K12 education account (I don't believe this applies to you)
- Your organization has restricted public sharing (this sounds plausible; is there an administrator you can check with)
I assume this used to work at some point; when did you last see/use functionality?