With eyes on the future of the fediverse, I would prefer not ending up with another Facebook-like situation where 'one place' is the 'default' place - where the 'default' place is run by people less trustworthy than Mark Zuckerberg.
It won't. There will be different federations with different politics, specially on the NSFW content, corporatism level and global militantism. All these instances will be incompatible and will defederate and refederate differently.
You will have a Microsoft instance, which will never federate with google or facebook or amazon or Apple. They won't share their customers. Lower brands will probably federate for techsupport for example, etc. This will be interesting to watch.
lavender