Indeed, as despite your scorn of their faith, Christians are taught to prepare for death, and know that this life is simply a speck in eternity, though it is to be taken very seriously, and it is here where we decide where we will spend the next life, and that there is eternity.
Thus Job would see his loved ones shortly if they were on the Lord's side, while the replacement family excelled that which was taken.
However, your objections are based on unbelief, but they do not apply when dealing with how a believer as Job would feel.
"11 Then came there unto him all his brethren, and all his sisters, and all they that had been of his acquaintance before, and did eat bread with him in his house: and they bemoaned him, and comforted him over all the evil that the Lord had brought upon him: every man also gave him a piece of money, and every one an earring of gold.12 So the Lord blessed the latter end of Job more than his beginning: for he had fourteen thousand sheep, and six thousand camels, and a thousand yoke of oxen, and a thousand she asses.13 He had also seven sons and three daughters.14 And he called the name of the first, Jemima; and the name of the second, Kezia; and the name of the third, Keren–happuch.15 And in all the land were no women found so fair as the daughters of Job: and their father gave them inheritance among their brethren.16 After this lived Job an hundred and forty years, and saw his sons, and his sons' sons, even four generations.17 So Job died, being old and full of days." (Job 42:11-17)
"11 Behold, we count them happy which endure. Ye have heard of the patience of Job, and have seen the end of the Lord; that the Lord is very pitiful, and of tender mercy." (James 5:11)
Quite true; if Job’s original family were, as we Christians put it today, saved by faith, then they’d all meet joyously in eternity.