Game example 1:
You walk into an area, there are the following quests available from a NPC:
- Kill 10 bandits
- Collect 10 apples
- Move 10 crates from A to B
Game example 2:
You walk into an area where you can participate in an event consisting out of:
- Kill bandits
- Collect apples
- Move crates from A to B
One activity gives 1 point, you need 30 in total to complete the event.
As you progress through the game and its different areas, sometimes bandits will be spiders and apples will be pears, but in the end the activities themselves do not change. You don't have to pick up every quest, just as you don't have to participate in every event.
Over time, you might favor "killing" quests, just as you might favor the "killing" part of the event, depending on your play-style. The end result is the same, even the perceived "freedom of choice" in example 2 becomes largely irrelevant the longer you play. You kill, you collect and/or you move stuff.
Now, please explain to me why example 1 is a boring grind, while example 2 is so much fun. Keep in mind that you will be doing either example the same amount of times.