Why does explain_statement require a function?

[nightpool]

Hi, I'm installing Postgres DBM to monitor my hosted Postgres database, and I'm trying to understand why it requires us to create a new custom function. Obviously, this requires us to make a change to our database's schema, which requires a lot more care and review, adding friction to the adoption of DBM.

Why is a custom function required? What is the benefit to Datadog of executing the custom function, versus executing a normal EXPLAIN (FORMAT JSON) statement directly?