In practice we except the patent to be rejected by a government department which value is measured in number of granted patents, or a special court which is infamous known to favor patents over rejecting them and which previous chief Judge was himself a previous patent lawyer.

The cost of getting a patent invalid is also very minor. There is no requirement to pay back the extracted rent by the time the patent get invalidated. The author also has many chances to rewrite a challenged patent and remove over broad claims. The risk vs reward of making broad claims in patents is evidentially in favor of risk.