For LLMs: For the most part, yes. However, an agentic loop, a sufficient knowledge base about chemicals & reactions, and some simulation tools to help judge, can come up with a top 5 promising solutions/approaches, which can then be tested in a lab. Faking what scientists might try themselves, just faster.

Then there are the non-LLM specialty AI models, which are increasingly being developed. Probably developed and trained by a small team of domain experts with the help of a coding agent, and seeded with domain-specific datasets.

The times ARE changing, but I would not expect Little Johnny to be whipping up bioweapons with chatbots anytime soon.