For people who truly care, grief can last a lifetime. For those who don't, it can be gone in a week. It's also important to remember that grief is very different than anger at the person for choosing to CTB, as we can only assume they were in enough pain to go and made the decision after much thoughtfulness and weighing the pros and cons.
For me, I feel little to no empathy for dead people. I wish I were them. Sometimes I miss people, but that isn't necessarily the same as wanting them back in their own living hell and disrespecting their choice to CTB.
Dead people have what I want. But sometimes, I selfishly want them to be here, not for their sake, but for mine, because I miss them.
My grandfather chose to die. He didn't CTB necessarily; he just quit taking the medications he was given while hospitalized and dying of COVID-19.
Do I sometimes wish I could see him? Yes. But it's important to remember that he was in pain and wanted to be free from it, which I respect. I would feel much worse if he was still alive and still living a painful existence just because I asked him to.
I miss people who died while wishing they could live much more. I want people to be happy, and if that means staying alive, which I personally can't imagine wanting, I want them to have the choice. Equally, if someone wants to die, regardless of whether I'll miss them, I want them to have the choice.
Most people in my life would barely miss me. My sister and my best friend would probably miss me every day. My mom thinks she would miss me, but she'd really just miss the fake image she set up of a happy, healthy little girl that she's been holding on to since I was a teenager and she realized I'm transmasc and depressed. All of her friends would feel the same ("so so sad, poor girl.............. ANYWAYS, how did your tennis match go?") and think they care without really, so they'd probably think about me for about 5 minutes once a year and move on with their lives immediately. I hope my dad would miss me, but I don't know him well enough to say for sure and he talks more to my mom about me than he does to me.