You get a ton of shock value, but it becomes so barebones at the end of the series because there's so few people left. I only know two series that did this, and they all fell off a cliff afterwards.
You can't go back and change the beginning, but you can start where you are and change the ending.
-Misattributed to CS Lewis
Not a ton of character but I remember a Netflix series where Sean bean played the lead role. I said to my step sister he's gonna die. She's like he's the main character though. I said doesn't matter that's Sean bean he always dies.
Sure enough he did final episode of season 1. He kinda got better though.
Story was based on Frankenstein and well he became the monster
I put my heart and soul into my work and I fear I have lost my mind in the process
Id prefer if every MC died at the end it would probably make people more cognizant that they too will die and maybe be nicer to people (because time here is short).