I was mostly kidding. But the little bit that bothered me was the idea that 'it is so simple here are 8 pages to barely scratch the surface.'

cron works fine for me. And if I ever have to work in an environment where I can't use cron and systemd is available, then of course I will use it. Thus far that has never been the case.

Do you believe that there are other implementations that do the task better and simpler?

All of 'em. If a joke took 8 pages to explain, it wouldn't be funny either. Lennart's cancer can go, thanks.

My favourite - and I've gotten into arguments with people about this who clearly never just tried it to see what happens - is it never executes things with the shell you think it will.

So many people assume that just because their script says #!/bin/bash at the top that cron is going to run it in bash. The reality is without ALSO setting SHELL=/bin/bash in the crontab file, you're getting your system's lowest-common-denominator shell (ash/dash/sh/whatever other gross abomination).

So much time wasted debugging. And I'm generally pretty good at avoiding shell-specific syntax, I've seen the abominations of shell scripts some people write.

The one thing I do wish systemd timers offered is cron syntax backwards compatibility, rather than just its ISO8601-style time patterns. An every-5-minutes job that used to be */5 * * * * is now OnCalendar=*-*-* *:0/5:0 and I'm just not sure that syntax is universally an improvement.

[your] root mail will fill up your disk and crash the system

If your ~mail/root is more than 0-length, you're missing valuable information.

yes and yes and yes, except:

Cron jobs are nice and simple to create.

So are systemd timers. Seriously. I understood this sort of argument in the years when systemd was relatively new, but nowadays ... c'mon, it's 2 config files in a very simple (the simplest form is just 2 headings with one variable definition each) and common format and (optionally) one command to reload the daemon.

Maybe adding a line to your list of cron jobs is slightly quicker, but you have none of the things systemd offers on top.

OK, tbf I don't know how much (ana)cron provides. Cleaning up the process tree? Restart conditions? Avoiding service duplicates? Advanced starting & repeating like "5min after boot" or "only after this other service has succeeded"? Can it read abbreviations like 'daily' or does it all need to be in that cryptic cron syntax?