The equipment and ppe for bio weapons and chemical weapons of the same health hazard is about the same.
well i think it strongly depends on your threat model. consider small leak of sarin: effects are detectable in seconds to minutes, antidote is readily available, cheap and specific, and sarin poisoning is not transmissible. in case of, say, plague, you won't know what's going on for days in which time there's already a risk of infecting some random passerby, which is highly suboptimal if you want to stay covert
In either case your logic is relying on a threatening actor to not have any education
it's not that i assume no education, it's that i (as an organic chemist) wouldn't trust crystallographer or electrochemist with synthesis of something like sarin. even with all required PPE and other precautions, your recruiting poll drops from about 100% (IED carrying child soldier) to maybe 1-0.1%? and that's even before you consider that some of these highly specialized chemical weapons people are already on military payroll, or are surveilled precisely for this reason
you're underestimating cost of this entire enterprise, which even at lab scale could easily go into hundreds of thousands to million dollar range. you're underestimating how hard it is even when you have everything provided - look at iraqi chemical weapons program. with no need to stay particularly covert they were only able to manufacture mustard gas of useful quality that could be stored; their mid tier chemical weapon sarin was at something like 30% purity and had very short shelf life; their vx was so dirty it was straight up useless
for some weird reason you're assuming that whatever chemistry you want to do, it works on the first try. it won't; it never does, and even if it did, you have to make sure you've got the right stuff. this makes synthesis only half of the problem, because there's still purification and analysis
you seem to ignore that even in the paper that you cite, anyone that doesn't have to do chemistry, doesn't. (by that i mean performing some reaction, that generates side products, and so requires purification, analysis, and generates waste stream). doing chemistry means generating waste and need of its safe-ish disposal; it means getting considerable PPE; it means getting precursors, maybe in large amounts; all of that might move you from government watch list to government act list.
talib doesn't do chemistry when he makes an IED, because melting down contents of TM-62s or UXO found in nearby field isn't chemistry; unabomber stuffing match heads in a pipe isn't chemistry; stealing cylinders of chlorine (bulk of fatalities in that paper) and putting it in a car bomb isn't chemistry. chlorine is not something you make and put in cylinders, because it's relatively hard, uses large amounts of energy, leaves considerable waste/side product stream, and you can order it on aliexpress. same goes for sulfur mustard, i'm pretty sure most of incidents happened in syrian civil war and ultimately this stuff can be traced to syrian or iraqi chemical weapons program
most of these problems, but especially making sure you've got the right stuff, are much harder for living organisms than for clearly identifiable, publicly known compounds. and we're still nowhere close to the point where llm gets potentially useful. no, getting B in high school biology and relying on gpt4 and scihub to get all the way up there doesn't count. chatgpt writing out rna sequence to be printed out, engineered into a bacterium and spread by a cultist, all done by mail order and or in garage is scenario completely detached from any pretense of being realistic
beakers, Bunsen burners, and filters
this tells me that you've ended all contact with chemistry on (classical, aqueous) qualitative inorganic analysis, because if you tried to cook anything on bunsen burner in organic lab, that'd be pretty hard considering there are none in flammables area. have you considered that you're severely out of your depth and got caught in openai's fear based hype-marketing?
e: if you want to isolate anthrax from dirt, you'll have many more problems than that, especially with "getting the right stuff" part. there are places where anthrax is endemic, but if step 1 involves catching diseased marmot in southern mongolia or deer in eastern siberia, this devolves straight into rube goldberg machine of mass destruction area