This is wrong. Inexperienced devs should ignore this.<p>One of my products heavily uses jsonb fields for storing JSON strings from external systems. We have partners that store data as JSON, so we store it as JSON as a kind of untouched log (ELT instead of ETL, I suppose).<p>If you store a schema somewhere (in, say, JSON Schema format), then your jsonb isn't schema-less when you parse it. Postgres may not understand the schema, but not all of your data transformation is going to happen in Postgres anyway.<p>Jsonb is also good for caching and logging things like REST request/response bodies if you ever need to query those later.<p>So in short: if the I/O format is JSON, then jsonb is appropriate.
Two kinds of people who read this: 1) Ah, good to know, this will prevent me from making mistakes 2) You're telling me there's _never_ a good reason...? Hmmm...