While the SSPL should be recognized as a copyleft open source license, since the OSI has refused to accept it, it's not really any different than the BSL at this time. If the OSI did their actual job, and promoted open source and helped foster a business-friendly open source license that prevented Amazon from sherlocking everyone, it'd probably see major adoption.
Copyright/copyleft licenses deal with your ability to publish the original work or derivative works, as well as performances of the derivative work.
SSPL requires you to publish items which may be non-derivative work on certain kinds of performances. Further, it does so specifically to be punitive against certain kinds of use (e.g. use by a competing company).
Because of the requirement to release so much non-derivative work under SSPL, including infrastructure you may not have written yourself or own copyright to, it is likely infeasible for one to be conformant to that provision.
The Problem with SSPL is, it triggers at runtime. Most OpenSource Licensens trigger at compile time. GPL ... you pull in GPL Code, compile it, your code becomes GPL. SSPL? Triggers at runtime if you run it as a SaaS, not really making clear what counts as SaaS, not really making clear what counts as a third party, etc. Thats the reason it should NOT be recognized as a open source license.