This raises a more philosophical argument as to what signifies the fall of a body like the Federation.

The Federation is a union of other bodies who through the spirit of cooperation decide to work together. If the majority of the bodies that make it up decide to pull out, does that constitute the fall of the Federation?

If one body leaves, of course it has not fallen; and if they all leave, it no longer exists at all. How many planets still need to be in a union for the Federation to successfully exist?

The fact that Vulcan/Ni’Var and Earth both pulled out and are two of the Charter members is certainly notable (though it doesn’t prove the fall of the Federation).

If it felt like the Federation had been weakened but was slowly rebuilding, I would agree with your idea that the blow to the Federation was meant to show its resilience; but the fact the Federation was not picking up steam at all (and felt much more in decline), to me indicates that the writers intended for us to interpret this as the Federation in its death throws until the Discovery showed up.

Perhaps this speaks to my own mindset as opposed to how the writers intended it, but it’s certainly how it came across to me.

As an aside, it could be interesting to explore what a Federation not primarily influenced by human/Vulcan influence could look like, as well as explore the idea of what constitutes the Federation (for example, could you have a Federation with no planetary members made entirely of individuals who have left their planet in the name of galactic brotherhood?). I am not sure the Federation is still in a place where such concepts could be explored, but it could certainly be interesting…