I think you're right in that some soul is lost. Anything which grows too much will fail as a community. However, as this is all !fs the important thing to remember is that these are mere tools to create our own, new and balanced communities.
I for one have seen many Twitter users come and go in floods to the !fediverse, some staying to create instances of #GNUsocial I think are despicable and don't agree with. But they are only a problem if you lack moderation.
Instead of "web-scale" we should think "human-scale".