That tool is only available in the latest versions of Postgresql (11 and 12), which very few stable shops are running in production.
Checksums were introduced in 9.3, yet not made the default until 9.6. Converting it requires lengthy downtime, back to the original author's point of major version upgrade pain.
Everything worthwhile in PG is introduced over a long time, requires a lot of pain to adopt, and if not adopted quickly, suddenly becomes "lol why aren't you doing this it's been there for years." That's the disconnect between people who actually run these clusters and the somewhat ivory-tower views of the postgresql devlopers.
Checksums were introduced in 9.3, yet not made the default until 9.6. Converting it requires lengthy downtime, back to the original author's point of major version upgrade pain.
Everything worthwhile in PG is introduced over a long time, requires a lot of pain to adopt, and if not adopted quickly, suddenly becomes "lol why aren't you doing this it's been there for years." That's the disconnect between people who actually run these clusters and the somewhat ivory-tower views of the postgresql devlopers.