Duncan is underplaying his accomplishments here.
Having three books, 21 published papers and four supervised PhDs within six years of your PhD is outstanding. Not too long ago he'd have been offered a Chair for this sort of stuff, not left to burn out on precarious contracts.
Professional news: my contract at Leiden ends this month so I'm leaving academia. I'm good at my job. I publish a lot (3 books, 21 articles/chapters), got great teaching evaluations and supervised 4 PhDs since finishing my own in 2016. It's not enough though.