> typically in PostgreSQL you just use text type and not impose any length restrictions unless absolutely necessary.

There was a horror story posted on here a while back about some old API causing an outage because there happened to be a random text field that a user was effectively using as an S3 bucket. Their conclusion was to always set a sane length constraint (even if very large, say 1MiB for the smallest fields) on field sizes.

Hyrum's Law. Yes user input validation, blah blah, but that is infinitely more surface area than having a sane (or absurdly large) limit by default.