In billiards, as in other dexterity-based sports, I believe there's a "sweet spot" of skill where the game is most enjoyable. At first, every pocketed ball is a pleasure because there's a higher chance of missing. Then, it quickly becomes about pocketing two, then three balls, until you clear the table. Once you start expecting to clear the table, you become less proud of yourself when you don’t succeed, and it turns into a pursuit of details and self-improvement.
In my opinion, the most fun level in billiards is being able to clear a 9-ball rack once per evening.