Matter is a polished reading app: articles, newsletters, highlights, audio. If you save essays and want to read them well, it does that. ceevo is for everything you save that is not an essay.
Matter turns links into a reading queue. ceevo turns links into folders. If most of what you save is long-form writing, Matter or a similar reader is the better fit. If most of it is tools, references, videos, and things to send people, ceevo is.
A reading app is a to-do list in disguise. Every unread item is a small debt. That is fine when the items are articles you chose to read, and wrong when they are a Figma plugin, a hotel, and a GitHub repo you might need in March.
ceevo has no queue and no unread state. A folder is a shelf, not a list of obligations. You open it when you need something from it.
Folders you name, a note next to the links, and a public page for any folder. The last one is what readers cannot do: you make a folder public and it becomes a page at ceevo.me/you/folder-name that anyone can open without an account.
Read in Matter, keep in ceevo. They are not really competing for the same link.