I think both have their use cases. For quick and dirty things (like manual logging/system performance), cron works just fine and is quicker to set up. For tasks that require dependencies or have to happen at very specific points in time (like immediately after the network services are started), systemd is more suited to the task.

There are of course quite a few people who dislike systemd for justifiable reasons (but I doubt it receives the disdain that SELinux does), here's a starting point:

https://ihatesystemd.com/

That said, I very much like systemd and I hope it isn't going anywhere. I think it's improved on a lot of things from the SysVinit days and I hope and believe that its shortcomings will be addressed and improved in the future.

I so much more prefer people to respond with reasons than say you should use abc, why, because it’s better

except systemd will be replaced by something else soon whereas cron has been around for a while.