OrgNote. The project is still quite raw but the developer works hard and the overall idea and philosophy behind the project is perfect for me. Fully compatible with emacs org-roam, most probably compatible with logseq. There is a “fully managed” free version with PGP support or an option for a self-hosted server.
Project: https://github.com/Artawower/orgnote Manifesto: https://github.com/Artawower/orgnote/wiki#manifesto
It is based on files in org format. But it is not related anyhow to org-agenda and planning. It is an only obsidian-like note-raking system with web+mobile+desktop and some blogging capabilities (public/private notes, etc.)