It’s not an issue. As long as .social is able to maintain the load.
The good thing about decentralization is that at any moment anyone could open a new instance and it would work perfectly fine. It does not matter if one instance have more or less users.
If it lowers the entry barrier it is welcome. It should not matter at all.
The thing about the fediverse is that it’s incredibly easy to make an instance and they are all compatible. So if any instance becomes evil people just have to seamlessly move away.
It’s not like twitter where if the owner become evil there’s nothing to do. Here you just move instance and be done with it, still the same platform, still the same users.