Both
The viva is a challenge. The majority of candidates pass.
Candidates are talented because of the time and work spent on their PhDs. Candidates need to take time after submission to prepare for the viva.
Most candidates are nervous. Most candidates feel confident.
Challenging but passing. Talented but taking the time to get ready. Nervous and confident.
We have to accept these strange dualities; often, with these seemingly contradictory states and feelings about the viva, it’s the case that both are true.