Then suicide is preferable.
Stop using the word suicide as if it was an insult.
And I've seen enough suffering and death to know that not everybody shares your opinion. I've seen people who, when they were healthy, held opinions just like yours beg for death when their time had come.
Count your blessings that you've not known pain, fear, or panic like the dying do.
^^ That's an opinion, phrased as if it was a fact. It's a value judgement and nothing more. I respect that it's your opinion, but just because you fervently believe it doesn't make it objectively true.
If you wish to engage in a meaningful and productive conversation, you'll need to be more honest about separating your opinions from fact. I think that, underneath all the shouting, you have a very interesting take on the issue. I'd like to discuss it. But it's drowned out by your inability to recognize that other people can have a different -- and equally valid -- interpretation of what "quality of life" means.
(Also, no: You cannot "decide things" about excruciating pain. It takes over a person's ability to reason. Chronic, debilitating pain very much robs a person of their agency.)
The fact that you can identify what my opinion is and still not address it, preferring to have this semantic argument, is a great example of someone avoiding the conversation because they know they're in the wrong.
People failing to realize a truth doesn't make it less true.
Peaceful death is suicide, if chosen. Period.