Ease of access matters. To read those textbooks you have to basically be a chemist and know where to find them, which books etc. An AI model can just tell you step by step and even make a nice overview of which chemical will have the most effect.

Id compare it to guns. You can't just buy guns here in the corner store in most of Europe. Doesn't mean they are impossible to get and people could even make their own if they put enough effort in. But gun violence is way lower than the US anyway. Because really most people don't go that far. They don't have that kind of drive or determination.

Making a fleeting brain fart into an instantly actionable recipe is probably not a great idea with some topics.