I'm sure you have probably viewed photography of the vastness of the Universe & all the different types of galaxies of which it is composed. The uncountable numbers of stars contained therein is beyond the comprehension of human intellect. Each galaxy contains 100 billion or more stars. Within the range of our most powerful telescopes are at least a billion galaxies. Yet the Universe in which we live is of finite size, it is not endless, however what we can see is a mere fraction of its vastness. God's wisdom & knowledge dwarfs this vastness.
No life has ever been detected anywhere else in all this cosmos, the image of carbon based life-form such as we humans are is unique to one rocky planet in all the vastness of the cosmos. There appears to me to be a revealing in the pages of Holy Writ that our human life-form is indeed unique in all the vastness of the cosmos. When you consider that the numbers of the galaxies in the Universe outnumber the total numbers of human beings who have ever lived & died on earth, it then becomes unimaginable to human intellect how the vastness of this cosmos sustains itself, why it just never collapses & ceases to exist taking us with it. Those of us in the field of science will tell you it is the Laws of Conservation of Energy & the 1st & 2nd Laws of Thermodynamics whereby the universe sustains itself, but what is it that sustains those proven principles of science?
In the book of Psalms it is stated by God that he has given names to all the stars of the cosmos. Why would he give names to the stars? Are they created beings of a life-form different from ours? Job 25:5 also states that they are not "pure" in his sight & that he calls them all by name Ps 147:4. This is scriptural evidence to suggest that the stars of the morning (Job 38:7)who sang with God at the creation of the earth also have a complement of stars (created beings) who live under the heavens even as we humans live under heaven. These other stars who are presntly under God's heaven because they followed Satan in rebellion and were bound in place inside the galaxies of the universe until the time of their judgement comes as described in Jude verse 6, the environs of the galaxies of the universe beneath God's heavenly abode appears to be their present place of restraint.
Read Job chapters 38 - 41. It is Ecc 3:11 vastly expanded upon. These chapters are God's response to Job for the same questions you pose in this forum. Why?. If you notice he did not even answer Job's question of "Why?". In the previous paragraph I've pointed out that there are scriptural hints as to why the universe with all its galaxies contained therein is so big, it appears to contain populations of created beings much different from us. However the flames of the fires of their luminescent existence sears no flesh for the sensation of pain. These rebellious beings feel no sorrow for their rebellious nature, they also cannot procreate, we were made different, we are superior to them because we feel pain & sorrow & procreate, they cannot.
If God had not created us with the capacity to feel pain & sorrow, we could not become sons & daughters of a God who will one day qualify us to judge rebellious angelic beings, 1 Cor 6:3. Judges must have a capacity for empathy for those in whom they stand in judgement, that capacity of empathy cannot be found in those impervious to afflictions of pain & sorrowful feelings caused by pain we see in others. Remember the scripture in which Christ states that even the demons believe & repent not? Now maybe you can understand better why they don't repent, no pain, no gain.