"Is it a blessing to live long on the earth?"
The book of Job answers this question to a large degree. He certainly didn't feel blessed when he was in torment from Satan. Many can relate to this:
Job 3 - Job wants to die, wishes he was never born.
But the "Second part" of Job's life was blessed, and fruitful. He was able to enjoy many aspects of a good life on earth:
Job 42:12-16 - Job's second part of his life blessed more than formerly.
Addressing your question in more depth: King Hezekiah was especially fond of worshipping in truth and purity. After all of his good works, he found he was going to die. But God blessed him with longer years:
2 Kings 20:4-6 - Hezekiah's years extended.
Psalms states the righteous will live forever upon the earth:
Psalm 37:29 - Righteous possess the earth.
As you probably know, Adam and Eve, as well as their immediate descendants lived a very long time (almost 1000 years), and gradually the human life span declined to 80 years/average.
Without naming too many verses, Christ himself as well as his followers raised people back to life on earth.
Back to the Example of Job, and the second part of his life - the bible implies by examples and statements that humans can expect to live a long time on earth, resurrected, enjoying beauty and prosperity they did not have formerly, in an emotionally, physically, and spiritually healed state. Its a comforting thought for those who have been struck with poverty, disease, and various troubles which cripple advantages in this present world.
The book of Job applies to the human race in general - especially those pleasing to their creator.
*To answer your question: * Just as we wish to serve our creator, seeking his interest -- he is always taking the lead in seeking our interests, such as those he put into our hearts:
Ecclesiastes 3:11 - Put eternity into the hearts of man.
Revelation 21:3 - Tent of God with Mankind.
It is indeed a great blessing to live a long time on the earth, and its one that has been put into our hearts and instincts. Its the renewed earth, not under the power of the wicked, which we will unquestionably feel blessed to live in.