I think your question is quite broad and is a combination of answers:

1. It takes a lot of effort to become a moon! Many likely formed from catastrophic planetary events that took place over billions of years. Some likely got caught in the gravitational pull of a planet eventually end up crashing into it. The moons we see now have attained relatively stable orbits, allowing them to survive.
2. Moons being much smaller than planets like Jupiter, resulted in them being discovered much later in human history. As you can see, new ones are still being discovered! These are new things to study! Exciting!
3. Our own moon is much larger compared to our own planet, and played a major role in how life developed over time. As mentioned, its own gravitational pull has influenced the earth enough to moderate its own orbit/spin/wobble. Its gravitational forces generate tides and help power circadian development of all life on earth! Evolution on earth is generally powered by the ebbs and flows of changes caused by the moon , spin/orbit of the earth, and gravity (among other things).