You'll hit all sorts of other fun problems by vertically scaling. - Many concurrent connections to a single database which Postgres has traditionally not handl

You'll hit all sorts of other fun problems by vertically scaling. - Many concurrent connections to a single database which Postgres has traditionally not handled well (though improved in recent versions). - You're now on the hook for writing a database control plane. - Backup and restore is much flakier since the data volume is so much larger. Lots of weird shit starts happening when you download tens of TB. - In general, everything is a harder once you start nearing machine limits.