Could you recommend/point out some of those essays? Cheers!

There is the - mentioned in another comment in this branch - dinstinction of real world experiments and "tricky" data. To my understanding LLMs are good in areas they have in part covered in their training data. The biological, chemical and physicial world is full of effects we have not measured yet, or not measured to a sufficient precise degree.

That would be my argument. The question is, however, not whether LLMs can develop drugs on their own, but what advances they will bring.