Fine except for one small point: you're wrong.

There is a name for herbal medicines that work; medicine.

Spider webs are not an anti-coagulant but a coagulant. When examined for medical use the effect was found to small compare to other materials and spider webs are quite difficult and expensive to collect, package, use. There are simply much better materials.

One good topical coagulant is made from shells of shrimp and it works quite well, if not without issues. Clearly medical science has no difficulty with cheap materials. Shrimp shells are typically considered a waste product. People pay to them removed. So much for the mythology about not being able to make money off cheap materials.

Digitalis is used. But typically not in herbal form. Herbs have issues in absorption, standardizing dose and purity. Most modern medicines are based on natural materials but purified and in standardized doses. The problem is that many herbs have little to no effect>

The effect is easy to see in Aspirin and willow bark. Willow bark works because it contain salicylic acid you could, in theory boil up a few cups of willow bark tea to get an equivalent dose. But implementing it is where it all falls apart. The amount and bioavailability of the salicylic acid in willow bark is not consistent. So how many cups do you make? Do you just guess?

The way it went down is how it should have. Recognizing the effect of willow bark tea the active ingredient was isolated and synthesized. It was found that salicylic acid is easier to manufacture from synthetic materials than extract it from bark. Now you can get the proper dose by simply unscrewing a cap and popping a few pills. Unlike boiling up tea with bark you have a very good idea of what is in each pill.

There is no chance that anyone who develops a cure for cancer will suppress any cure. Come up with a cure that stands up to testing, with a demonstrable and repeatable effect,and people will beat a track to your door. Funding will not be an issue.

Yes, there will always be more money available for research in popular diseases. Rare diseases will always struggle for money. On the other end of the scale we have three very reliable drugs to give guys an erection. Millions of men are willing to pay fifteen dollars a dose to get their little fellow to stand at attention.

It is also easy to overestimate how effective drug companies are. Drugs and disease are international. When the drug companies demanded more money than Brazil and China wanted to pay the drugs were simply reverse engineered them. Both nations produce their own supply of anti-HIV drugs. Yes the drug companies are rich, politically powerful, and they have a lot of influence. But they weren't going to invade Brazil.

The idea that there is a vast water tight conspiracy of all the drug researchers, all the producers, all the employees, in every nation is just silly. Humans just aren't that good at keeping secrets.

I don't like drug companies much. They are manipulative, greedy, conniving, power hungry and heartless. They aren't going to do anything they can't make a profit on. That is capitalism.