Poster implies that a benefit of globally centralised structures like Twitter, FB and LinkedIn is verification. I think impersonation is rife there, and will be less on Mastodon. Apart from basic measures (rel-me verification against your website, use your own domain for an instance), there are similar to T/FB/LinkedIn ways to verify someone outside the platform itself, where people check it's you through a channel they already know it's you. Above all the potential benefit of impersonation does not exist on M: no immediate global audience, no amplification of messages through self-feeding loops of engagement. Your reach is limited to your own follow(er)s mostly, and they won't fall for an impersonation, as you're already there among them. The power assymmetry inherent in T/FB's algo's doesn't exist on M. So impersonating would cost the impersonator way more, and become unsustainable to them.