Assume that meta starts managing the largest instances, and makes a bunch of changes that give actually useful features that other instances don't adopt (assume they require some meta oversight or other bs). What happens when meta starts using their clout to start suggesting more changes moving forwards, further alienating those instances and maybe getting less people to use them. Then you have issues maintaining some niche communities that are not under meta's instance, so info is naturally funneled back into a meta instance. And then meta does something to essentially lock down the use of their instance so you have to give them your personal data in order to view the data generated by the community in the meta instance.

I've actually seen this happen personally with people growing cordyceps mushrooms. There is a big active group on Facebook that discusses their tips and tricks, but you have to log in to be able to see their info now.

Despite a lot of people here being more or less fine with the current growth, there absolutely needs to be growth so that some of the niche communities will migrate here so that info can't be locked down.