Comment by petereisentraut

It's a bit more complicated than that. You will also notice another release note item in PG13 that says "Allow inserts, not only updates and deletes, to trigger vacuuming activity in autovacuum", which is because vacuum is not only about cleaning up deleted or rolled-back rows, but also transaction ID wraparound. Making that go away is also a dream of many, but it's a different (or additional) project than a new storage system.