pgbench is in the postgresql-client-common package [0], but the actual
per-version binaries are in the server package, e.g., postgresql-16 [1].
If you try to call pgbench without installing the server package, it
tells you
Error: You must install at least one postgresql-client-<version> package
but that is wrong advice in this situation.
Is there are reason for this arrangement?
(The same confusion applies to vacuumlo.)
[0]:
https://packages.debian.org/trixie/all/postgresql-client-common/filelist
[1]: https://packages.debian.org/trixie/amd64/postgresql-16/filelist