CodeIgniter4 - Event listner

No, I am not asking to define every possible event but only to help handle business logic.

I suppose despatching events can be useful to separate code e.g. a learner access their training, completes, and on successful completion receives pdf certficate by email. I can achieve all these through cron jobs by querying the database (select all records which have completion date today and looop through to send certficates out) or I suppose I could have listeners listening to specific events which do their job as dedicated piece of codes. I am just wondering if that's better way than having all my code in one file and using series of if/else.