Sorry I wrote this while listening to a melancholy soundtrack. Perhaps try listening to it while reading what I am about to say, to emphasis the words even stronger?
You seems unable to understand the serious problems of immortality. The immortality of oneself is the immortality of one's mind; Memory. Which means, absolutely zero memory lost. No memory wiping.
If one were to introduce cloning, memory downloading, memory wiping, memory transfer -- then that's no longer immortal. There will no longer be communication. There will no more needs to do anything. There will be no curiosity. There will be no effort, no motivation, and no security... ... ...
There will be no freedom.
Life would no longer make any sense.
It wouldn't be called life anymore.
It will become a plague of another kind.
One should not conclude that immortal is a good thing, neither everyone will going to like in the future, since you haven't felt what it is like, to be immortal. You don't know what it means to be immortal. Thus you don't know the consequences of being an immortal. You don't know how miserable is to be immortal.
What made you think we'll be forever happy? Have you gone through what needs to be answered?
That being said...
There are limits of information, this give one of the consequence for immortality. Consider that our memory will keep on growing, they will not be lost, being immortal means oneself, will always be oneself, one single copy, one single unique entity that lives on forever.
Information Limitation, and mental decay.
As our memory grows, which means there will be a time, where we will run out of information to receive. There will be nothing more information to learn, nothing unique, nothing curious, nothing exciting... Our life being immortal... will collapse into a state of emptiness, restlessness, dissatisfaction, repetitiveness, and boring... ...
Would you devote your entire immortal life, traveling through the empty space of the universe? You will know what I mean, when you play the game known as No Man's Sky.
Where is the happiness? Life must define a limit to be called "life".
Changing this rules of life will destroy its definition, and you'll become an enemy to enforce this ideology to the future by brute force.