Birthday Wishes for the Deceased don’t make sense

Basically the title. Why post happy birthday, or miss you, or thinking of you, etc etc? It’s not like they’re going to see it. Guess this is a good spot to note I don’t believe in any type of god or afterlife for reference. Recently saw someone post anonymously on YikYak wishing their dad a happy birthday who had died. Like, why bother with that, feels like attention seeking honestly. Thoughts?

Don’t come at me with the no empathy stuff please, just genuinely never understood why people do this stuff, has always seemed dumb to me.