It certainly exists, and in unexpected places, like system catalogues. It's especially visible if a (wrong) mgmt decision has been made to switch off autovacuum

It certainly exists, and in unexpected places, like system catalogues. It's especially visible if a (wrong) mgmt decision has been made to switch off autovacuum - then everything tends to blow up, and fast. In short: explicit bloat management and autovacuum tuning are a necessity for all high transaction rate workloads in PostgreSQL, and the stats need to be monitored closely to detect workload changes.