These are rigged. Igg changes the odds of a guardian appearing during guild fest so you’re forced to spend money buying gems. You can see for yourself if you pick that quest.
One of the easiest guild fest tasks to complete with the best point benefits IMO. Yes it can take a while to do, but I'll go out on a limb and say at least 95% of the time you will complete the 209 point, encounter 3 guardians quest long before you would spend the 30,000 stars on the 118 point spend 30,000 holy stars task. If you only have 2,000 stars, obviously don't do it if you're F2P and don't have another way to get them. But if you've saved stars and have 20-25 thousand of them, you can easily complete the 2 guardian and most of the time the 3 guardian task.