Like, Nextcloud runs background tasks as a cron job which is something I’ve never seen with other hosted services.
Drupal also uses crons to run repeated tasks. By default, Drupal cron cleans out stale database records for a few tables and breaks old caches. It can be extended by the developer, though.
It’s probably a holdover from before containerised applications were ubiquitous but honestly it comes off as jank.
PHP is pre-container and pre-virtualization, so I guess you can think of it as a hack way of getting garbage collection. To be honest, the cron’s translate pretty well to k8s cronjobs. You just use the same image as the app and override the command with the cronjob command.
That’s the neat part: they don’t!