It meets all the criteria and the only difference from AGPL is how much source code you have to release and when - which is also the difference between GPL and AGPL. It has problems, but being closed source isn't one of them.
The OSI will never certify it, of course, because that would go against the business interests of the OSI members. The OSI is a consortium of companies who receive free labour from permissively licensed projects and to a lesser extent GPL projects, and it would like that to continue, which it cannot in practice under SSPL. The OSI article linked in a reply does not make a single point against the open-sourceness of the SSPL, and essentially just says they don't like it, and that some companies won't be able to comply, which is true of every free software license.
The FSF, Debian, etc haven't decided one way or another because it's not a very widespread license and they can just use valkey instead of wasting the effort.