Why did God curse Adam with hard work? He didn’t. The earth went wild without Adam in charge. I think God really only described the new situation.
Animals began to be wild, too. Some became dangerous to people.
God had blessed Adam and Eve and given them dominion over all the earth. Their choice had ruined the situation. But God could not curse those he had blessed.
Really, the worst part is that they had brought sorrow and fear into their lives.
But the future holds a new earth for those who love God. There will be plenty of room because there are no oceans.
See Revelation 21:1