Mongodb is gone; everyone stopped using it. The publicly traded company behind it with thousands of employees and over a billion in revenue is a figment of your imagination.
It's kind of like how Java still exists but doesn't commonly run in browsers in the form of a Java Applet. It exists behind the scenes and I'm sure many who used to use it now use it indirectly.
It's sort of as if it's gone. TFA is about what I no longer recognize as what I used to mean when I talked about redis. Since the license change the project with the trademark no longer fits that concept. Valkey does. I'm not sure where I ca find something that fit my old context of MongoDB.