SSH doesn't depend on certificate authorities, it's up to you to manage your own keys, each end point also has a uniquely generated signature which avoids MITM after first time auth (including by taking over domains).
This is a HTTPS only issue and fundamentally it's the same problem as control over domains (ease of manipulation through centralisation).
This is a HTTPS only issue and fundamentally it's the same problem as control over domains (ease of manipulation through centralisation).