Very demanding task, but appreciated by riders.
I remember my dad organising them. Start sheets, all typed up by hand, same for result sheets. Using Banda copying machines.
No spreadsheets or computers in those days, no electronic payments, all manual work. And they had full fields, so entries had to be posted to 120 riders and those who didnt get in.
Today's IT systems might be complcated, but must be better than the old days.
I haven't organised an event myself, but was the results keeper for our evening 10's for about 15 years and the time and commitment is indeed demanding.