To say more: I have sometimes had to resort to writing a wrapper script just for the purpose of gatekeeping what stdout/stderr a task in cron does (and ensure the exit code is properly (non-)zero.

At one former job where I had a lot of cron jobs, I even wrote a re-usable wrapper utility for it.

Many unix command line executables are pretty bad at it (especially if you deal with anything proprietary), so I get why people resort to just throwing away output from cronjobs, although it is a problematic lack of observability, true.