Rather than big and small #fedi I prefer thinking of deep and shallow, or perhaps hard and soft fedi.
To me how big it is, is less important than whether and to what extent it fulfils its own technical and social values: access, customisation, permissionlessness (as in you don't have to be special or especially blessed by a special person or organisation, not as in don't ask consent), freedom from surveillance, advertising, influence operations, commercial exploitation, algorithmic supremacy or informational asymmetries.
I'd like everyone who wants to access fedi and who is willing to abide by its norms to have easy and hopefully free access to it. That doesn't mean bringing in those who are uninterested or hostile, nor does it mean bringing people in at all costs. But it does mean scalability, interoperability, efficiency and so on do matter.
So neither big nor small: deep fedi, true to itself.