I think the only way to remedy this is by use of digital identities. Maybe some collaboration with Civic or similar projects. If we can limit the system to 1 account per person that should fix some of the problems.

But I am doubtful this will happen anytime soon, if ever, because digital identities aren't quite there yet.

I also wonder.. if you can just make many accounts, what's to stop somebody from self-voting themselves into Witnesses? Take that one step further: What's to stop somebody from self-voting multiple of their own witness accounts into power?
Take that one step further: what's to stop somebody from taking over the entire system this way over time? Game theory says that if it's possible and profitable, it will happen one day.