It's difficult to explain, but — you can feel it, right? When it tells you how this world is beyond saving.

[ kaeya thinks back to when it was his turn to go through this process, wondering when was it that they finally gave in. it felt like the last possible moment but... ]

I can't tell you how you're meant to accept it, exactly; it's something you have to come to terms with yourself. If you disagree with what it's saying, then it's much harder.