Moons aren’t very special, they’re just debris that’s been captured by the gravity of a planet. Earths moon doesn’t “make earth livable” it makes earth more livable, and it’s not that important to life as we know it.

Jupiter has many moons surrounding it because it’s the second largest (in both size and (more importantly) mass) object in our solar system, so many things are captured by its gravity. Many of these satellites (not like our man-made satellites, simply something that orbits a planet) are large and -importantly- reflective. When moons are highly reflective, we have a much easier time spotting them because they shine with the sun’s light. However, smaller and less reflective satellites are much harder to discover.

Finding these Jupiter moons is less about the moons themselves, but instead the means in which we were able to detect them. More sensitive tools and techniques are being developed, leading to more discoveries day after day.