Death does leave an absence, there being sorrow, pain, and anger is warranted. But life is very short, we will all go and be in a similar place or time, soon. We will all rejoin. Whether it be in a void, devoid of the shackles of humanity, peace forever. Or maybe a different time in a different place as something or someone else.
That's why death doesn't make as sad or worried anymore. We will all share and be together soon.