We always hear of projects that are 'hard work', but what are some successful projects/platforms that were relatively smooth sailing?

We always hear of how much hard work it is to build a successful startup and survive the first 5 years. Blood, sweat, tears, late nights, pivots and scrambling to make things happen etc. But what are some projects that actually had a pretty cruisy run?

Maybe they were completely bootstrapped? Maybe the founder just stumbled upon a really easy simple idea that required next to no maintenance?