Hydrogen cyanide will turn into “cookie dough” in 1-5 years. Which is way shorter than “forever”.
The way you said it in your first comment made it seem longer lasting than radioactive waste. Which it isn’t according to the linked PDF. That is the only point I was trying to make.
I don’t get this either or mentality.
It’s possible to improve the status quo by doing multiple things.
When a curtain in your home catches fire, you don’t go “I’ve already called the fire brigade, why should I bother getting the fire extinguisher in the hallway?”