If you want a super secure platform for private communication use Matrix for fucks sake, this is a media aggregator and social network.
Use the appropriate tools for the appropriate use-cases.
Everything on Mastodon gets publicly posted. Like, what even is this?
Security and accessibility are always at odds with each other.
You don't increase security and safety and also increase accessibility. No, by increasing security, you have decreased accessibility.
Security and accessibility are a balance. If it's easily accessible, it's not secure, if it's secure, it's not easily accessible.