The best part of the fediverse is that anyone can run their own server. The downside of this is that anyone can easily create hordes of fake accounts, as I will now demonstrate.
Fighting fake accounts is hard and most implementations do not currently have an effective way of filtering out fake accounts. I’m sure that the developers will step in if this becomes a bigger problem. Until then, remember that votes are just a number.
IMO the best way to solve it is to ‘lower the stakes’ - spread out between instances, avoid behaviors like buying any highly upvoted recommendation without due diligence etc. Basically, become ‘un-advertiseable’, or at least less so