Why do you assume most will be lost to hell? None are now in hell (except the grave) -and most misunderstand what the bible says on the subject.
It is possible that none will be lost.
Make work project? You mean we didn't pop out knowing how to do things correctly and needed to be taught? That's about right.
After 4 boys, you should understand why God limited man's lifespan to 120 years.
Gen 6:3 And the LORD said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.