There are atheists who try to make a virtue of necessity by saying mortality is what makes life precious. It's actually immortality that cheapens the value of life.
However, you have secular transhumanists who hope to achieve immortality by digitizing the mind, then uploading the contents into video games. An indestructible simulated paradise.
If atheists who say mortality is what makes life valuable had a shot at immortality, would they turn it down? Really? Eventually, they might become bored and commit suicide, but would they turn down the initial offer?