I disagree it’s up to you to conclude it would have been better if he had been killed 3 years earlier (which you imply).
In general you don’t have the right to such a statement.
Now, if you were discussing _your own_ condition this would be a totally valid consideration IMHO. But you (almost) _never_ have the right to conclude from someone elses part when it’s their time to go.
Assisted suicide is a humane option but ”I hope he had died with some dignity years ago instead of pissing everyone off” tarnishes the entire concept and is exactly the type of argument which stops assisted suecide becoming a more widely accepted option.