Because you profit from those inventions ? You might be saved by the drug discovered by Alphafold

What you're using to type this message was made possible by research spending.

Or we could do like before: let the church help the poors, the nobles take decisions and the peasants make the food. Like that, everyone has its clear and simple role and you wont complain of taxes: you ll have no revenue :)

Basically what you're saying is governments should never give grants only loans.

Maybe government should invest in companies instead of giving grants. So if the company fails, it is money lost like a grant, but if there is success, then the government can get its money back.

Then you would have state capitalism, and the government might be biased towards state owned enterprises, ruining the free market.

Good news, there's no free market to be ruined. Free markets are a fiction. Governments already influence the market in far, far more extreme ways than this.

So long as any profits from these investments are not ploughed back into general revenues, your concerns are moot. For example, you could establish an independent body—let's call it INVEST1—to oversee these investments. INVEST1 would be required to divest ownership of successful enterprises at a threshold that ensures money spent roughly matches money earned (and thus self-funding). Once it reaches a stable equilibrium, you spin off INVEST1 as a fully independent not-for-profit. Government then establishes INVEST2 and the process starts again from the beginning. Rinse and repeat.

Loans that only come due upon breakout success, more precisely.

The argument is that Humanity's past knowledge and labour is a common heritage of everyone. Anybody that benefits from it must, at least in part, pay back "the commons" for that benefit.

So you get to leech off the greatest minds in the present while they are living and again after they are dead?

So when people build off humanity's past knowledge and they pay for the privilege I assume the new knowledge that is created does not belong to humanity any longer and belongs to individuals?

I don't get what you mean. How do you mean "leech"? The point is that anyone — actually let's take a concrete example, Google and Deepmind — when they produce something, that was due in part to their own labour and in part to the heritage that the past generations and the current fellow humans have given them. Therefore, in principle, some of the fruits of their success belong to them and some belong to society. It's now a matter to discuss the split ;)