Without going on a whole dissertation, there are a lot of aspects that have to be figured out for a government sanctioned execution to occur.

You could in theory just have an officer whip out a shotgun and bang, problem solved, much like you mentioned with suicide. But when it's sanctioned by the government you have to be very discerning with a lot of different details.

Why are we ending this person's life

Because we have deemed their actions excessively heinous and do not want them to drain further on society by being incarcerated

In ending their life should we be causing them pain?

Huge debate, but the main reason we use lethal injection or gas executions instead now is to end their life without pain or torture. Ideally a person would just be turned off like a light without them even noticing.

How can you be sure you got the right person

Big question, but we are talking execution

What if the execution fails or goes incorrectly, now we've maimed someone and caused undue suffering, which as a people we have decided we wouldn't do.

Exactly. That's why there are so many issues surrounding lethal injection chemicals and sources. How do you create these chemicals properly and precisely, without spending excess money or profiting off govt sanctioned murder.

Why not carbon monoxide?

Short answer, it's flammable and dangerous to the people performing the executions. That's why nitrogen is a decent possibility for something like this, it is inert, common, and can be acquired and vented away with little issue.

Not only are there plenty of people who have no problem with it, there's plenty of people who will be upset the killing wasn't more barbaric.

And it's pure blood-lust. They know the criminal can never reoffend. They know the death won't bring back the victims or bring peace to their family. They know it won't stop other people committing the same crime. They weren't impacted by the crime in the slightest and don't seem to have any real compassion for those who were.

But they want to see the criminals fry anyway.

Threads like this make it extremely clear the the reason the western world isn't executing women in soccer stadiums is because the people who make those decisions said "no", not because it wouldn't draw a crowd.

This isn't experimentation and it isn't new. I fucking hate this talking point. It's a well-established, safe, and potentially harmless method, unlike the shit we were doing before.

Still doesn't make it right.